mesa+ annual report 2011
DESCRIPTION
Annual Report 2011 MESA+TRANSCRIPT
ANNUALREPORT 2011
MESA+ AnnuAl REpoRt 2011
General
Preface..... ............................................................................................ 5About MESA+, in a nutshell ...................................................................6MESA+ Strategic Research Orientations ..........................................8Commercialization..................................................................................16The Dutch Nano-landscape ................................................................18National NanoLab facilities ................................................................20International Networks.........................................................................22Education ...................................................................................................24Awards, honours and appointments ...............................................26
HiGHliGHts
BES Biomolecular Electronic Structure .................................32BIOS BIOS Lab-on-a-Chip .............................................................. 33BNT BioMolecular Nanotechnology ......................................... 34CBP Computational BioPhysics .................................................. 35CMS Computational Materials Science .................................... 36COPS Complex Photonic Systems ................................................ 37CPM Catalytic Processes and Materials ................................. 38ICE Interfaces and Correlated Electron systems............... 39IM Inorganic Membranes.......................................................... 40IMS Inorganic Materials Science ...............................................41IOMS Integrated Optical MicroSystems .................................... 42LPNO Laser Physics and Nonlinear Optics .............................43MCS Mesoscale Chemical Systems ..........................................44MnF Molecular nanoFabrication ................................................ 45MSM Multi Scale Mechanics ........................................................ 46MST Membrane Science and Technology .............................. 47MTP Materials Science and Technology of Polymers ............48MaCS Mathematics of Computational Science ............................ 49NBP Nanobiophysics ..................................................................... 50NE NanoElectronics .................................................................... 51NEM NanoElectronic Materials ................................................... 52NI NanoIonics ............................................................................... 53NLCA Nanofluidics for Lab on a Chip Applications ..................54OS Optical Sciences .................................................................... 55PCF Physics of Complex Fluids ................................................. 56PCS Photocatalytic Synthesis .................................................... 57PIN Physics of Interfaces and Nanomaterials ....................58PNS Programmable NanoSystems ........................................... 59PoF Physics of Fluids ................................................................... 60PGMF Physics of Granular Matter and Interstitial Fluids ....61QTM Quantum Transport in Matter ........................................... 62SC Semiconductor Components ............................................. 63SFI Soft Matter, Fluidics and Interfaces ............................... 64ST PS Science, Technology and Policy Studies ...................... 65TST Transducer Science and Technology ............................ 66
Publications
MESA+ Scientific Publications 2011 ...........................................70
about Mesa+
MESA+ Governance Structure .....................................................76Contact details .................................................................................76
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[PREFACE]
2011 - The Year Between2011 was a year between two major Nanotechnology programmes: NanoNed had come to an end and NanoNextNL
had just started. With the launch of NanoNextNL a new period was heralded in, in which innovation research grants
became available to the Dutch nanotechnology community. The main difference between these two national
programmes is the focus on valorisation and collaboration with industry. This is completely in line with another
topic that marked 2011: a new Dutch Government programme on innovation called 'topsectors', i.e. strong industrial
areas reinforced by the joint research and development of Dutch industry, research institutes and universities, and
science foundations. MESA+ was fervently involved in both these initiatives. First, through the roll out of NanoNextNL
with significant contributions from several MESA+ research groups. Second, by actively participating in the updated
research agenda of the national nanotechnology roadmap. Over the coming years it will become clear whether and how
this new strategy of the Dutch Government to stimulate innovation through active interaction between industry and
institutes such as MESA+ will prove to be a sound alternative to the successful programmes NanoNed and NanoNextNL.
2011 was also the first year of actually running the new NanoLab at MESA+. Obviously, starting up such a complex new lab
is no trivial matter; in fact you could say it is quite a challenge. But apart from a few minor setbacks, when the time came
the inauguration went very smoothly, thanks to the users and technicians. The number of visitors who are motivated to
learn more about nanotechnology and wish to see the new NanoLab is significant and still on the increase. Furthermore,
the organisation of this Dutch national facility, NanoLabNL, has been formalised and is certainly prepared for the future.
2011 was also a year in which MESA+ realised a significant increase in the number of research groups. A rearrangement
of research at the University of Twente resulted in an expansion of MESA+, which increased to 34 research chairs and over
525 researchers, including more than 300 PhD-students.
2011, a year between a very successfully period of developing into a mature institute and a period marked by a challenging
future with new opportunities.
Ir. Miriam Luizink, Technical Commercial Director, Prof. dr. ing. Dave H.A. Blank, Scientific Director,
MESA+ Institute for Nanotechnology MESA+ Institute for Nanotechnology
“MESA+ Institute for Nanotechnology is one
of the largest nanotechnology research institutes in the world”
MESA+ Institute for Nanotechnology is one of the largest nanotechnology research institutes in the world, delivering competitive and
successful high quality research. MESA+ is part of the University of Twente, and cooperates closely with various research groups
within the university. The institute employs 525 people of whom 300 are PhD candidates or postdocs. With its NanoLab facilities the
institute holds 1250 m2 of cleanroom space and state of the art research equipment. MESA+ has an integral turnover of approximately
50 million euros per year of which 60% is acquired in competition from external sources (National Science Foundation, European
Union, industry, etc.).
MESA+ supports and facilitates researchers and actively stimulates cooperation. MESA+ combines the disciplines of physics,
electrical engineering, chemistry and mathematics. Currently 34 research groups participate in MESA+. MESA+ introduced Strategic
Research Orientations, headed by a scientific researcher, that bridge the research topics of a number of research groups working
in common interest fields. The SROs’ research topics are an addition to the research topics of the chairs. Their task is to develop
these interdisciplinary research areas which could result in new independent chairs. Internationally attractive research is achieved
through this multidisciplinary approach. MESA+ uses a unique structure, which unites scientific disciplines, and builds fruitful
international cooperation to excel in science and education.
MESA+ has been the breeding ground for more than 45 MESA+ high-tech start-ups to date. A targeted program for cooperation
with small and medium-sized enterprises has been specially created for start-ups. MESA+ offers the use of its extensive NanoLab
facilities and cleanroom space under hospitable conditions. Start-ups and MESA+ work together intensively to promote the transfer
of knowledge. MESA+ has created a perfect habitat for start-ups in the micro and nano-industry to establish and to mature.
MESA+ is a Research School, designated by the Royal Dutch Academy of Science. All MESA+ PhD’s are member of the MESA+ School
for Nanotechnology, part of the Twente Graduate School.
About MESA+, in a nut shell
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[RESEARCH]
Mission and strategyMESA+ conducts research in the strongly multidisciplinary field of nanotechnology and nanoscience.
The mission of MESA+ is:
n to excel in its research field;
n to explore (new) research themes;
n to educate researchers and engineers in its field;
n to commercialize and valorize research results;
n to initiate and participate in fruitful (inter)national cooperation.
MESA+ has defined the following key performance indicators for achieving its mission:
n scientific papers in high ranked jounals like Science or Nature;
n 1:1 balance between university funding and externally acquired funds;
n sizable spin-off activities.
MESA+ focuses on three issues to pursue its mission:
n to create a top environment for international scientific talent;
n to create strong multidisciplinary cohesion within the institute;
n to become a national leader and international key player in nanotechnology.
Organizational structure
MESA+ is an institute of the University of Twente and falls under the responsibility of the board of the university. The scientific
advisory board assists the MESA+ management in matters concerning the research conducted at the institute and gives feedback
on the scientific results of MESA+. The governing board advises the MESA+ management in organizational matters. The scientific
director accepts responsibility for the institute and the scientific output. The managing director is responsible for commercialization,
central laboratories, finance, communications and the internal organization. The participating research groups and SRO program
directors form the MESA+ advisory board.
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[RESEARCH]
university board
advisory board:• strategic research orientations
• research Groups
scientific Director/technical commercial Director
scientific advisory board Governing board
nanolabManagement support
Dr. Pepijn W.H. Pinkse:
"Applied NanoPhotonics:
there's more
to light than
meets the eye"
Optics has revolutionized fields as various as data storage and long-distance communication. Optical systems have a chance
to become even more ubiquitous in other areas, like today’s smart devices, but this step requires further miniaturization. The
example of electronics shows us that miniaturization will sooner or later hit physical limitations. In the case of optics this will
be in the nanodomain. Working with optics on this scale requires new concepts to be developed and many questions to be
answered:
How can we shrink the dimensions of optical structures to or even below the wavelength limit? To what extend can we build
so called ‘’meta-materials” that have specially engineered optical properties by nanostructuring? How can we miniaturize
lasers, reduce their threshold and increase their yield? How can one make high-sensitivity optical detectors, e.g. for medical
applications, and integrate them in low-cost labs on a chip? And on the more fundamental side: Can single emitters be controlled
efficiently and embedded into nanophotonic structures? Can we use nanophotonics to study complex (molecular) systems and
can we tailor light to efficiently steer their behavior? Are there opportunities to exploit the quantum character of light for new
functionality?
The goal of our SRO is to address these questions exploiting the expertise in MESA+ groups. Building adaptivity into nanophotonic
systems will be a common paradigm in answering these questions. Adaptivity allows optimizing properties or processes with
clever learning algorithms. Adaptive systems can react on external stimulus, can compensate for fluctuations and inevitable
randomness in nanophotonic structures.
Applied NanoPhotonics
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[StRAtEgiC RESEARCH oRiEntAtionS]
Applied Nanophotonics (ANP) started in October 2009 with the arrival of Pepijn Pinkse from the Max Planck Institute for Quantum
Optics in Garching to become ANP program director at MESA+. ANP fosters new research and develops new expertise on a few
key areas. For instance by means of ANP group meetings, colloquia and workshops, ANP stimulates cooperation between the
research groups at MESA+ that have a strong optics focus including COPS, IOMS, LPNO, NBP, and OS.
Program director: Dr. P.W.H. Pinkse, phone +31 53 489 2537, [email protected], www.utwente.nl/mesaplus/anp
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[StRAtEgiC RESEARCH oRiEntAtionS]
ANP in action at the open air Museum in Ootmarsum. In 2011 we organized our second
yearly workshop with over 70 participants from the MESA+ groups COPS, IOMS, LPNO,
NBP & OS.
Data taken in an ANP collaboration with the groups COPS and
OS. Visible are Near-field Scanning Optical Microscopy images
of propagating light in a photonic-crystal waveguide. For specific
wavelengths and locations, Anderson-localized light is observed
(purple highlights) [S.R. Huisman et al., arXiv:1201.0624v1.]
Dr. Peter M. Schön:
"What makes Nanotechnology possible?
There are many important driving
forces to mention, but for sure one of the
most influential was the development
of scanning probe microscopies.”
The Strategic Research Orientation (SRO) Enabling Technologies has started its activity in January 2011. It is a multi disciplinary
program aiming at bundling the research activities of MESA+ in a very important enabling area in nano technology, that is
Scanning Probe Microscopy.
Of key interest for the SRO are scanning probe microscopies for nanoscale electrochemistry and novel combinations with optics/
spectroscopies. Enabling Technologies aims to foster research and expertise in the field of nanoscale electro chemistry and
electrical probing. For instance by means of ET group meetings and workshops, the strategic research orientation Enabling
Technologies aims to stimulate cooperation between the research groups at MESA + that have a strong interest in nanoscale
electrochemistry and electrical probing. With respect to novel combinations of scanning probes with optical techniques the
collaboration with the SRO ANP provides an excellent base.
Towards an ultra-high speed AFM with chemical sensitivity
The research groups Materials Science and Technology of Polymers (MTP) and Physics of Interfaces and Nanomaterials (PIN)
work in collaboration aiming to integrate STM and electrochemistry into AFM. The approach will encompass the combination of
tunnel current sensing AFM and SECM (scanning electrochemical microscope). Novel spectroscopic modes are in development for
these hybrid atomic force microscopies with the key objectives of chemical imaging and reactivity studies at the molecular level
under various conditions, for instance in a liquid environment. As model systems molecular layers on conducting substrates will
be investigated, such as self-assembled monolayers (SAMs) on gold and phthalocyanine layers comprising different central ions.
Enabling Technologies
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[StRAtEgiC RESEARCH oRiEntAtionS]
[StRAtEgiC RESEARCH oRiEntAtionS]
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Poster price for Hairong Wu
Hairong Wu (second person on the right side)- PhD student bridging between the groups MTP and PIN
and funded from the SRO ‘Enabling Technologies’ won two times a poster price. The first time was at the
Dutch Polymer Days 2012 in Lunteren, the second time at the ISPAC 25th 2012 conference. This picture is
taken on the ISPAC conference. Left: Prof. dr. Pavel Kratochvíl (Institute of Macromolecular Chemistry,
Czech Republic (ISPAC)). Right: Prof. dr. ir. Peter J. Schoenmakers (University of Amsterdam).
HIGHLIGHTED PUBLICATION: R. Heimbuch, H. Wu, A. Kumar, B. Poelsema, P. Schön, G.J. Vancso, H.J.W. Zandvliet, Temperature dependent transport study of a single octanethiol molecule, submitted
These systems shall be used for initial fundamental chemical identification and
reactivity studies.
Program director: Dr. Peter M. Schön, phone +31 53 489 3170, [email protected],
www.utwente.nl/mesaplus/enablingtechnologies
Nanomedicine Healthcare faces new challenges in the 21st century. Populations are evolving, and life expectancy continues to increase in
developed countries. Consequently, new classes of diseases which are related to ageing must be handled, and a new paradigm of
“healthy ageing” has been identified by the EU as a priority. Furthermore, the healthcare system must become more competitive,
and drastically reduce its overall expenses. To address these issues, novel and more appropriate approaches must be developed
for disease detection and treatment.
Cancer -which is the first cause of death in developed countries- is a good example where traditional medical approaches fail for:
(i) early disease detection, (ii) efficient, localized and personalized treatment, and (iii) non-invasive tissue analysis for diagnosis
and prognosis. A reason for this failure lies in the difference in scales between traditional medical techniques and molecular
processes involved in disease development. Diseases are primarily correlated with molecular and nm-scale phenomena such as
DNA mutations, dysregulation in protein functioning, while medical approaches mostly work at the scale of a whole organism or
tissue.
In that context, the advent of nanotechnology that deals with the manipulation of matter at the sub-100 nm scale is expected to have
a tremendous impact in medicine. Using nm-size tools offers exciting new possibilities such as probing and acting at the subcellular
or molecular scale; which enables to bridge the gap between traditional medicine and molecular processes.
Nanomedicine is the particular sub-field of medicine where structures originating from the parent field of nanotechnology are employed
to derive new approaches for diagnosis, imaging, treatment, and to get better insight into molecular events involved in disease
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[StRAtEgiC RESEARCH oRiEntAtionS]Dr. Séverine Le Gac:
"Nanotechnology offers new
approaches to medicine for early
disease detection, for targeted,
localized, personalized treatment, and for
better understanding of molecular
processes involved in diseases.”
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[StRAtEgiC RESEARCH oRiEntAtionS]
processes. Nanotechnology-based protocols bring new capabilities in terms of localized,
specific and targeted in vivo protocols, for both imaging and treatment. For diagnosis and
fundamental analysis, nm-size structures and miniaturized sensors present the required
detection sensitivity to determine the molecular signature of a disease, for instance using a
single cell analysis approach, which is essential for patient-specific treatment.
Nanomedicine is an interdisciplinary field, requiring expertise from various disciplines
such as medicine, engineering, chemistry, biophysics, and biology. The MESA+ Institute
for Nanotechnology covers all these disciplines with the development of nanosensors,
miniaturized point-of-care devices, inorganic and organic nanoparticles, nanostructures,
new nanomaterials, and biomolecule analysis.
In 2012, the SRO will first make an inventory of existing research at MESA+ related to
nanomedicine. Thereafter, promising research lines will be identified on which MESA+
can profile worldwide in the field of nanomedicine, and around which the activities of
the SRO nanomedicine -or nanotechnology for innovative medicine- will be organized.
Program director: Dr. ir. Séverine Le Gac, phone +31 53 489 2722, [email protected],
www.utwente.nl/mesaplus/nanomedicine
NanoMaterials for Energy The worldwide energy demand is continuously growing and it becomes clear that future energy supply can only be guaranteed
through increased use of renewable energy sources. With energy recovery through renewable sources like sun, wind, water, tides,
geothermal or biomass the global energy demand could be met many times over; currently however it is still inefficient and too
expensive in many cases to take over significant parts of the energy supply. Innovation and increases in efficiency in conjunction
with a general reduction of energy consumption are urgently needed. Nanotechnology exhibits the unique potential for decisive
technological breakthroughs in the energy sector, thus making substantial contributions to sustainable energy supply.
The goal of the Strategic Research Orientation (SRO) NanoMaterials for Energy is to exploit and expand the present expertise of the
MESA+ groups in the field of nano-related energy research. Through multidisciplinary collaboration between various research groups
new materials with novel advanced properties will be developed in which the functionality is controlled by the nanoscale structures
leading to improved energy applications. The range of new research projects for nano-applications in the energy sector comprises
gradual short and medium-term improvements for a more efficient use of conventional and renewable energy sources as well as
completely new long-term approaches for energy recovery and utilization.
Ultra-thin piezoelectrics for energy harvesting
Piezoelectric materials can transform mechanical energy into electrical energy and vice versa. Because of that they are used in
a multitude of everyday applications from gas lighters to inkjet printers and from ultrasound generators in medical applications
(echography devices, blood sensors, lithotripters) to vibration dampers (in cars, skis, helicopter blade). However, piezoelectric
materials have the potential to play an even greater role in society by harvesting the energy that is wasted ubiquitously as vibrations
(from cars, house appliances, industrial machine) and transforming it into electricity. But in order to fulfill our dream of paving roads,
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[StRAtEgiC RESEARCH oRiEntAtionS]Dr. ir. Mark Huijben:
Breakthroughs in energy
applications can only be
accomplished by manipulation
of novel materials on the
nano scale.”
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[StRAtEgiC RESEARCH oRiEntAtionS]
railways and homes with piezoelectrics, these materials have to be made lighter, thinner and
less toxic than the ones available today (which contain heavy chemical elements).
An important step into this direction has been achieved by collaboration between Guus
Rijnders and co-workers (IMS, MESA+ Institute for Nanotechnology, University of Twente),
Beatriz Noheda (RUG, Zernike Institute for Advanced Materials), the CIN2-Barcelona and
the CEMES-CNRS Institutes in Toulouse and Zaragoza. The results have been published in
Nature Materials.
The researchers have shown that ultra-thin films (with thickness of about 100 atomic layers)
of piezoelectric materials deposited under carefully designed conditions, self-organize
and flex at the nanometer scale in periodic fashion. This produces huge strain gradients
(large differences in the distances between atoms) in such a way that a new mechanism to
produce piezoelectricity can take place (so-called flexoelectricity). This greatly increases
the materials response at these small thicknesses. Moreover, this novel way of producing
piezoelectricity is less dependent on the chemical composition and will allow non-toxic
and more readily available materials to be investigated for piezoelectric energy harvesting
application.
Program director: Dr. ir. Mark Huijben, phone +31 53 489 4710, [email protected],
www.utwente.nl/mesaplus/nme
HIGHLIGHTED PUBLICATIONS: [1] G. Catalan, A. Lubk, A. H. G. Vlooswijk, E. Snoeck, C. Magen, A. Janssens, G. Rispens, G. Rijnders, D. H. A. Blank, B. Noheda, Flexoelectric rotation of polarization
in ferroelectric thin films, Nature Materials 10 (2011) 963-967. [2] H.J. Chang, S.V. Kalinin, A.N. Morozovska, M. Huijben, Y.H. Chu, P. Yu, R. Ramesh, E.A. Eliseev, G.S. Svechnikov, S.J. Pennycook, A.
Borisevich, Atomically-resolved mapping of polarization and electric fields across ferroelectric-oxide interfaces by Z-contrast imaging, Advanced Materials 23 (2011) 2474.
[CoMMERCiAlizAtion]
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Nanotechnology offers chances for new business. Around knowledge institutions, stimulated by a dynamic entrepreneurial
environment, nuclei of spin-off companies arise. The number of new businesses based on nanotechnology is growing rapidly. MESA+
plays an important role nationwide, being at the start of more than 45 spin-offs. Access to state-of-the-art nanotech infrastructure,
shared facilities functioning in an open innovation model, is of crucial importance for both creation and further development of spin-off
companies. These spin-off companies are important for the national and regional economy; SMEs will become increasingly important
for employment and turnover. MESA+ intensifies and strengthens its commercialization activities to further increase the number of
patents, the number and size of spin-offs and, consequently, its national and international reputation.
High Tech FactoryMESA+ is establishing the High Tech Factory, a shared production facility for products based on micro- and nanotechnology. High
Tech Factory is designed to ensure that the companies involved can concentrate on business operations and focus their energies on
growth rather than on realizing the basic production infrastructure required for achieving that growth. In 2011 the first 500 m2 of
High Tech Factory labs have become available as production environment. Development of cleanrooms, labs and offices will continue
and is expected to be finalized by the end of 2012.
High Tech FundThe technical infrastructure fund High Tech Fund offers an operational lease facility for companies in micro- and nanotechnology.
Equipment is located in the production facility High Tech Factory. The 9 M€ fund, supported by the ministry of Economic Affairs, the
province of Overijssel and the region of Twente, was launched successfully in June 2010. In 2011 investments have been realized for
the companies SolMateS and Medspray.
MESA+ Technology AcceleratorWith the MESA+ Technology Accelerator, organized in UT international ventures (UTIV), MESA+ invests in early stage scouting of
knowledge and expertise with a potential interest from the market. The first phase of technology and market development is organized
in so-called stealth projects. A successful stealth project is continued as a spin-off or license. Through the initiative Kennispark, the
UT is applying the UTIV model more widely at the University.
Kennispark TwenteCommercialization of nanotechnology research is one of the very strong drivers of MESA+. As illustrated in the topics above, key
aspects of the MESA+ agenda encompass business development, facility sharing, area development, and growth towards a production
facility. With these key commercialization projects MESA+ contributes strongly to the Kennispark agenda and the provincial and
regional innovation systems.
Commercialization
[CoMMERCiAlizAtion]
The Dutch Nano-landscape The Dutch Nano-landscape The Dutch Nano-landscape The Dutch Nano-landscape
The Dutch Nano-landscape The Dutch Nano-landscape
The Dutch Nano-landscape The Dutch Nano-landscape
The Dutch Nano-landscape The Dutch Nano-landscape
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Netherlands Nano InitiativeThe nanotechnology research area is comprehensive and still extending. The Netherlands continually makes choices based on
existing strengths supplemented with arising opportunities, as is described in the NNI business plan ‘Towards a Sustainable Open
InnovationEcosystem’ (2009) in micro and nanotechnology. Generic themes in which the Netherlands excel are beyond Moore and
nanoelectronics, nanomaterials, bionanotechnology and instrumentation, while application lies within the areas of water, energy,
food, and health and nanomedicine. These generic and application areas are, when applicable, covered by risk analyses and
technology assessment of nanotechnology. NanoLabNL provides the infrastructure for the implementation of the NNI strategic
research agenda.
In 2011 an update of the nanotechnology roadmap has been established, and forms part of the ‘topsector’ innovation policy of the
Dutch government.
NanoNextNLNanoNextNL, the 250 M€ innovation program has started in 2011. NanoNextNL, a collaboration of 120 partners, proposes to apply
micro- and nanotechnologies to strengthen both the technology base and competitiveness of the high tech and materials industry
and to apply them in support of a variety of societal needs in food, energy, healthcare, clean water and the societal risk of certain
nanotechnologies. The main economic and societal issues addressed in this initiative are:
n the societal need for risk analysis of nanotechnology;
n the need for new materials;
n ageing society and healthcare cost;
n more healthy foods;
n need for clean tech to reduce energy consumption, waste production and provide clean water;
n advanced equipment to process and manufacture products that address these issues.
NanoNextNL covers all relevant generic, application and social themes.
the Dutch nano-landscape
[tHE DutCH nAno-lAnDSCAPE]
National NanoLab facilities National NanoLab facilities National NanoLab facilities National NanoLab facilities
National NanoLab facilities National NanoLab facilities
National NanoLab facilities National NanoLab facilities
National NanoLab facilities National NanoLab facilities
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National NanoLab facilitiesNanoLabNLNanoLabNL is listed on the ’The Netherlands’ Roadmap for Large-Scale Research Facilities’ as one of 28 large-scale research facilities
whose construction or operation is important for the robustness and innovativeness of the Dutch science system.
NanoLabNL provides access to a coherent, high-level, state-of-the-art infrastructure for nanotechnology research and innovation in
the Netherlands. The NanoLab facilities are open to researchers from universities as well as employees from companies. NanoLabNL
seeks to bring about coherence in national infrastructure, access, and tariff structure. Since its establishment in 2004 the NanoLabNL
partners invested about 110 M€ in nanotech facilities through their own funding and additional public funding.
The partners in NanoLabNL are:
n Twente: MESA+ Institute of Nanotechnology at University of Twente;
n Delft: Kavli Institute of Nanoscience at Delft University of Technology and TNO Science & Industry;
n Groningen: Zernike Institute for Advanced Materials at Groningen University;
n Eindhoven, Technical University Eindhoven and Philips Research Laboratories (associate partner).
Together, these four locations cover most of the country and offer the widest possible spectrum of nanotechnology facilities for
researchers in the Netherlands to use.
MESA+ NanoLabMESA+ NanoLab has extensive laboratory facilities at its disposal, offering a wide spectrum of opportunities for researchers in the
Netherlands and abroad:
n a 1250 m2 fully equipped cleanroom, with a focus on microsystems technology, nanotechnology, CMOS and materials and process
engineering;
n a fully equipped central materials analysis laboratory;
n a number of specialized laboratories for chemical synthesis and analysis, materials research and analysis, and device
characterization.
In 2011 MESA+ has invested largely in realizing its new BioNanoLab, part of the MESA+ NanoLab, for research in bionanotechnology,
nanomedicine and risk analysis.
The MESA+ NanoLab facilities play a crucial role in the research programs and in collaborations with industry. MESA+ has a
strong relationship with industry, both through joint research projects with the larger multinational companies, and through a
commercialization policy focused on small and medium sized enterprises.
[nAtionAl nAnolAb FACilitiES]
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International Networks(Inter)national position and collaborationsMESA+ has a strong international position, several strategic collaborations and is active in international networks and platforms.
MESA+ has strategic collaborations with: NINT (Canada), Ohio State, Materials Science Nano Lab (US), Stanford, Geballe Lab of
Advanced Materials (US), Berkeley, nanoscience lab Ramesh group (US), California NanoSystems Institute at UCLA (US), JNCASR
(India), NIMS (Japan), University of Singapore, and the Chinese Academy of Science CAS, and in Europe with: Cambridge, IMEC,
Karlsruhe, Munster, Aarhus and Chalmers University.
EICOONEICOON is the FP7 Euro-Indo forum for nano-materials research coordination & cooperation of researchers in sustainable energy
technologies. The consortium addresses the strategic assessment including synergy analysis of nano-materials research needs in
the EU and India. It establishes and communicates the mutual interests and topics for future coordinated calls to enable decision
and policy makers to make better informed decisions. Besides the assessment, the project also addresses the dissemination of the
"nano-materials research acquis" in the field by organization of events. Finally, it brings together researchers to exchange ideas for
joint projects for future research collaboration.
Visit the EICOON website for more information: www.eicoon.eu.
[intERnAtionAl nEtwoRkS]
International Networks International Networks International Networks International Networks
International Networks International Networks
International Networks International Networks
International Networks International Networks
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Impressions of MESA+ meeting
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EducationTwente Graduate SchoolMESA+ School for Nanotechnology
MESA+ is a Research School, designated by the Royal Dutch Academy of Science.
All PhD students are member of the MESA+ School for Nanotechnology which is part of the University of Twente’s Twente Graduate
School. The Graduate School is aiming to strengthen education and improve the skills of PhD students.
Master of Science NanotechnologyAccess to the best research students worldwide is critical to the success of MESA+. In the academic year 2005-2006 a master track
nanotechnology was started as the first accredited master’s training at the University of Twente. MESA+ invests in information to
students of appropriate bachelor’s courses, and brings the master’s nanotechnology to the attention of its international cooperation
partners.
The master Nanotechnology will be incorporated into the MESA+ School for Nanotechnology.
Fundamentals of NanotechnologyNanotechnology is a multidisciplinary research field, and requires expertise from the field of electrical engineering, applied physics,
chemical technology and life sciences. The course ‘Fundamentals of Nanotechnology’ is annually organized by MESA+ and provides an
initial introduction to the complete scope of what nanotechnology is about. The course is set up for graduate students and postdoctoral
fellows that are starting to work or are currently working in the field of nanotechnology. The workshop is given in an intensive one-
week format; participants attend about 20 lectures and labtours on different subfields of nanotechnology. Each year about 25 students
participate.
[EDuCAtion]
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simon stevin Meester 2011 The STW Technology Foundation has awarded Prof. dr. ing. Dave Blank the title of Simon Stevin Meester 2011. The prize was presented
on 6 October during a conference organized in honour of STW's 30th anniversary. The Simon Stevin Meester prize is the largest
award given for technological-scientific research in the Netherlands. The prize is intended for top researchers who are successful
in linking excellent fundamental scientific research to socially-relevant issues and applications.
Blank is the sixth scientist from the University of Twente/MESA+ Institute for Nanotechnology to have been awarded the Simon
Stevin Meester title. Previous winners include Detlef Lohse (2009), Albert van den Berg (2002), Cock Lodder (2002), Miko Elwenspoek
(1998) and David Reinhoudt (1998).
erc Proof of conceptProf. dr. Detlef Lohse (Physics of Fluids group) and Prof. dr. ir. Albert van den Berg (BIOS Lab-on-a-chip group) are among the first
European researchers who are granted the new European Research Council (ERC) Proof-of-Concept grant.
These 'top up' grants, worth up to €150,000 each, are designed to help in the valorisation of ERC-funded research. In total, 30
top researchers, already holding ERC grants, will be given this additional support to bridge the gap between their research and
the earliest stage of a marketable innovation. The funding can cover activities related to for instance intellectual property rights,
technical validation, market research or investigation of commercial and business opportunities.
erc starting GrantIn 2011 four young MESA+ researchers have been awarded the ERC Starting Grant of 1,5 million euros each. Dr. Regina Luttge of the
Mesoscale Chemical Systems group, Dr. Allard Mosk of the Complex Photonic Systems group, Prof. dr. Serge Lemay of the NanoIonics
group and Dr. ir. Michel de Jong of the NanoElectronics group. ERC Starting Grants aim to support up-and-coming research leaders
who are about to establish or consolidate a proper research team and to start conducting independent research in Europe.
VIDI grantDr. Nathalie Katsonis of the Biomolecular NanoTechnology group is the recipient of a Netherlands Organisation for Scientific
Research NWO Vernieuwingsimpuls VIDI grant (2011) on a project called “Nanostructured super-reflectors: learning lessons from
scarab beetles”. This grant of maximum 800,000 euros enables her to develop her own research topic and start a research group
of her own.
VENI grantThe Netherlands Organisation for Scientific Research (NWO) has awarded a VENI-STW grant to Transducers Science and
Technology researcher Dr. ing. Léon Woldering and Dr. ir. Floris Zwanenburg of the NanoElectronics group. With this prestigious
grant of 250,000 euro, both can develop their research ideas for a further three years. The topic of research of Léon Woldering
is ‘controlled three-dimensional self-assembly of silicon nanoparticles using hydrogen-bonds’. Floris Zwanenburg’s research is
focused on spin quantum bits in silicon quantum dots.
Marie Curie Career Integration GrantDr. Sonia Garcia-Blanco of the Integrated Optical Microsystems group and Dr. ir. Floris Zwanenburg of the NanoElectronics group
both won the Marie Curie Career Integration Grant of 100,000 euros. Marie Curie Career Integration Grants are intended to improve
Dr. Regina Luttge
Dr. Allard Mosk
Awards, honours and appointments
Prof. dr. Serge Lemay
Dr. ir. Michel de Jong
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considerably the prospects for the permanent integration of researchers who are offered a stable research post in Europe after a
mobility period in a country different from the country where the researcher has been active during the past years.
KncV Gold Medal Prof. dr. Jeroen Cornelissen of the MESA+ group Biomolecular Nanotechnology won the KNCV (Royal Netherlands Chemical
Society) Gold Medal. During the official opening of the international Year of Chemistry 2011 he received the Gold Medal, which is
regarded as the most important Dutch prize for young researchers who have excelled in the area of chemical research.
Valorization Grants phase 1 Dr. Burak Eral and Dr. Dileep Mampallil of the Physics of Complex Fluids Group are awarded an STW Valorisation Grant phase 1
of 25,000 euros for exploring the commercialization of a substantial improvement of a workhorse method in analytical chemistry:
Matrix assisted laser adsorption Ionization mass spectroscopy for short MALDI-MS.
Dr. ir. Wim van Hoeve, former PhD of the Physics of Fluids group, received the 25,000 euros STW Valorisation Grant for the
validation of a monodisperse microbubble generator. His grant is financed by FOM (Foundation for Fundamental Research on
Matter). Van Hoeve started the spin off company Tide Microfluidics.
Dr. Loes Segerink, PhD at the BIOS, Lab- on- a-Chip group received a valorization grant for the project “fertility chip, on-chip semen
analysis system”. The grant will be used to conduct a study into the technical and commercial feasibility of the fertility, in close
cooperation with the MESA+ spin-off company Blue4Green.
YES! Fellow FOM The Foundation for Fundamental Research on Matter has awarded a Young Energy Scientist (YES!) Fellowship to Dr. Süleyman Er
of the Computational Materials Science group. The former FOM PhD student will spend the next four years looking for a new class
of solar cell components that can convert sunlight into electricity more efficiently and at a low cost. With a YES! Fellowship, FOM
gives young researchers the chance to develop themselves at a top foreign institute in fundamental energy research.
Grant for Fertility InnovationDr. ir. Séverine Le Gac is one of the winners of the Grant for Fertility Innovation (GFI) of 200,000 euros at the 27th Annual meeting
of the European Society of Human Reproduction and Embryology (ESHRE) in Stockholm, Sweden on July 4th 2011. The grant will
focus on the application of microfluidic devices for the culture of human embryos.
Simon Stevin gezel Dr. Loes Segerink, PhD at the BIOS Lab-on-a-chip group has won both the jury and the public prize (1,000 euros each) of the STW
‘Simon Stevin leerling’ for her research on the "fertility chip" that can count sperm and measure their motility (ability of sperm
to move properly towards an egg).
Ercoftac Da Vinci award On 10 October, Dr. Richard Stevens received the Da Vinci Award 2011, which is awarded by the 'European Research Community
on Flow, Turbulence and Combustion'. Stevens gained his doctorate on 30 June 2011 in the MESA+ Physics of Fluids group of prof.
dr. Detlef Lohse for his thesis entitled 'Rayleigh-Bénard turbulence'. The Da Vinci Award is a recognition of his scientific work and
his talent for presenting data clearly. The prize consists of 1,000 euros, a certificate and a medal.
Dr. Nathalie Katsonis
Dr. ing. Léon Woldering
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Overijssel PhD award At the 50th Dies Natalis, Dr. ir. Martin Jurna, former PhD of MESA+ Optical Sciences group, received the 2011 Overijssel PhD award
for the best University of Twente thesis from last year. The award, 5,000 euros, was presented by the Queen’s Commissioner, Drs.
Ank Bijleveld. Martin Jurna received this award for his thesis ‘Vibrational phase contrast cars microscopy’.
Cum laude distinctionIn 2011 two MESA+ PhD candidates received cum laude distinctions for their work: Dr. ir. Hans Boschker of the Inorganic
Materials Science group for his thesis: ‘Perovskite oxide heteroepitaxy strain and interface engineering’ and Dr. Tian Gang of the
NanoElectronics group for his thesis on Inorganic-organic hybrid electronics.
Graduate programme MESA+MESA+ School for Nanotechnology received 800,000 euros from the Netherlands Organisation for Scientific Research (NWO)
for the training of four young researchers. The funding is part of NWO’s Graduate Programme and is aimed at encouraging the
development of Dutch PhD courses.
MESA+ meeting 2011During the MESA+ meeting 2011 in the Grolsch Veste on September 27, Ir. René Heimbuch, Physics of Interfaces and Nanomaterials
group, won the 1st prize for the best poster. The 2nd prize was won by Ir. Shuo Kang, NanoIonics group, and the 3rd prize by Ir.
Carmen Stoffelen, Molecular NanoFabrication group. The MESA+ meeting is to illustrate the various projects and programs of the
MESA+ institute by means of lectures and scientific poster presentations.
Appointmentsn From February 1, 2011 Prof. dr. ir. Alexander Brinkman is appointed as head of the new chair on Quantum Transport in Matter. The
research addresses quantum aspects of electronic transport in novel materials and devices. Examples of quantum phenomena
of interest are entanglement and teleportation. Materials under study are correlated electron systems such as superconductors,
oxides and their interfaces, and topological insulators.
n Prof. dr. ir. Leon Lefferts of the Catalytic Processes and Materials group has been appointed part-time professor at Aalto
University in Helsinki. At the Finnish university, he will carry out research into the production of hydrogen gas from biomass.
n Prof. dr. Vinod Subramaniam of the Nanobiophysics group received visiting professorship at University of Konstanz. He is also
appointed as extraordinary professor Nanoscale Imaging at the Radboud University Nijmegen, Faculty of Medical Sciences,
from December 1, 2011.
n Prof. dr. ir. Albert van den Berg has joined the board of the KNAW, the Royal Netherlands Academy of Arts and Sciences, in
June 2011.
n Prof. dr. ing. Dave Blank has become captain of science of the topsector board High Tech Systems and Materials.
n Ir. Miriam Luizink has been elected chairman of the board of the NanoLabNL association.
n NanoElectronics prof. dr. ir. Wilfred van der Wiel has become a member of the Global Young Academy. This Academy aims
to empower and mobilize young scientists to address issues of particular importance to early career scientists. Current working
groups focus on improving Early Scientific Careers, Science-Society Dialogue, Science-Education, and Interdisciplinary Research.
Dr. Loes Segerink
Dr. Sonia Garcia-Blanco and Dr. ir. Floris Zwanenburg
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Mesa+ annual rePort 2011
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Prof. dr. Claudia Filippi“Electronic-structure theory has dramatically
expanded the role of computational modeling,
enabling a detailed atomistic understanding of
real materials. Our research focuses on the
challenge to further enhance the predictive
power of these approaches while bridging to
the length-scales of complex (bio)systems.”
Why is Green Fluorescent Protein not green? A challenge for multi-scale modeling
We are currently interested in rationalizing the structural mechanisms underlying the optical properties of autofluorescent proteins, in
particular the homologues of Green Fluorescent Protein (GFP), a family of proteins widely used for noninvasive in-vivo imaging of cells
and tissues. Given the complexity of these photo-biological systems, theoretical approaches rely on multi-scale embedding schemes
to couple a quantum description of the photosensitive chromophore with a classical treatment of the rest of the protein. Contrary to
what is generally portrayed in the literature, we demonstrate that the use of a standard classical description of the protein does not
allow us to correctly predict the position of the absorption maxima of wild-type GFP and to reproduce the bathochromic shift in the
protein, which should be particularly significant for the neutral form. Because of these distressing findings, we are currently working
on the developments of novel approaches to treat chromophore-protein interactions beyond standard hybrid models.
HIGHLIGHTED PUBLICATION: C. Filippi, F. Buda, L. Guidoni, A. Sinicropi, Bathochromic Shift in Green Fluorescent Protein: A Puzzle for QM/MM Approaches, J. Chem.
Theory Comput., publication date (Web) November 21, 2011.
biomolecular Electronic Structure
The Biomolecular Electronic Structure (BES) group is a computational group
in the field of electronic structure theory and focuses on the methodological
development of novel and more effective approaches for investigating the
electronic properties of materials. Our current research centers on the
problem of describing light-induced phenomena in biological systems, where
available computational techniques have limited applicability. Deepening
our physical understanding of the primary excitation processes in
photobiological systems is important both from a fundamental point of view
and because of existing and potential applications in biology, biotechnology,
and artificial photosynthetic devices.
Figure: The Green Fluorescent Protein chromophore in its protein
environment.
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Prof. dr. ir. Albert van den Berg“We try to do top-level research
on micro- and nanofluidics and
new nanosensing principles, and
to integrate that into real-life Lab-
on-Chip systems for biomedical
and sustainable applications.”
In the BIOS Lab-on-a-Chip group fundamental and applied aspects of
miniaturized bioanalytical laboratories are studied. With the use of
advanced and newly developed micro- and nanotechnologies, enabled
by the MESA+ Nanolab facilities, microdevices with nanostructures for
medical and sustainable applications are realized, ranging from chips
for monitoring medication to counting sperm cells, and from discovery
of new biomarkers and ultrasensitive detection thereof to harvesting
electrical energy from water.
bioS lab-on-a-ChipAl2O3/Silicon NanoISFET with Near Ideal Nernstian Response
The multidisciplinary work presented here concerns Nanoscale ISFET (ion sensitive field-effect transistor) pH sensors that produce
the well-known sub-Nernstian pH-response for silicon dioxide (SiO2) surfaces and near ideal Nernstian sensitivity for alumina (Al2O3)
surfaces. Measured pH responses from titrations of thin atomic layer deposited (ALD) alumina (Al2O3) surfaces on the nanoISFETs
results in near ideal Nernstian pH sensitivity of 57.8 ± 1.2 mV/pH (pH range: 2 - 10; T = 22 °C) and temperature sensitivity of 0.19 mV/
pH °C (22 °C ≤ T ≤ 40 °C). A comprehensive analytical model of the nanoISFET sensor based on the combined Gouy-Chapman-Stern
and Site-Binding (GCS-SB) models supports the experimental results and an extracted ∆pK ≈ 1.5 from the measured responses further
supports the near ideal Nernstian pH sensitivity.
HIGHLIGHTED PUBLICATION: S. Chen, J.G. Bomer, E.T. Carlen, A. van den Berg, Al2O3/Silicon NanoISFET with Near Ideal Nernstian Response, Nano Lett. 11 (2011) 2334.
Figure 2: (a) and (b) pH behavior of SiO2 surfaces. (a) Bare SiO2 with
non-linear ∆Ids with increasing pHB. (b) Measured pHB-∆o of bare
SiO2 with measured and fitted response. (c) and (d) pHB-∆o response
of ALD Al2O3 surfaces. (c) pH titration direction showing the response
hysteresis. (d) Measured and fitted response for four different silicon
nanowire devices at T = 22 °C, ∆o / ∆pHB = 57.8±1.2 mV/pH; at T =
30 °C, ∆o / ∆pHB = 59.4±0.3 mV/pH; and at T = 40 °C, ∆o / ∆pHB =
61.3±0.8 mV/pH.
Figure 1: (a) High-resolution scanning electron microscopy
images of fabricated silicon nanowires. (b) Schematic of
electrical measurement, Inset: microscope image of polyimide
encapsulated device prior to testing. (SiN: low-stress silicon
nitride; Al: Aluminum; PI: polyimide).
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HIGHLIGHTED PUBLICATION: M. Brasch, A. de La Escosura, Y. Ma, C. Uetrecht, A.J.R. Heck, T. Torres, J.J.L.M. Cornelissen, Encapsulation of phthalocyanine supramolecular stacks
into virus-like particles, Journal of the American Chemical Society 133 (18) (2011) 6878-6881.
Prof. dr. Jeroen J.l.M. cornelissen“Using the building blocks from
Nature to make and understand
new technologies.”
encapsulation of Phthalocyanine supramolecular stacks into Virus-like Particles
Naturally occurring nanoparticles such as protein cages can be used as well-defined and monodisperse platforms for the organization
of chemical entities both in their inner cavities and on their exterior surfaces.
We developed a method to stack phthalocyanine dyes inside virus based protein cages. The advantage of using protein cages for the
formation of phthalocyanine stacks is i) the low concentration of phthalocyanine in bulk solutions second, ii) it is possible to control
the size and structures of such stacks, which allow an efficient way to determine the properties of these macrocycles and iii) the
enclosure of phthalocyanine inside protein cages make them suitable for medical applications such as photodynamic therapy.
To enclose phthalocyanine inside protein cages a water-soluble zinc phthalocyanine (ZnPc) and the native virus protein were simply
co-incubated in solution (Figure 1). Interestingly, capsids of two different sizes can be obtained, depending on the pH. At neutral
pH the formation of stacks inside the protein shell is favored, whereas the formation of dimers is favored at lower pH. In both cases
the stacking behavior and the optical properties can be followed by spectroscopy. The superior optical and electronic properties of
phthalocyanines together with the biocompatible nature of the protein cages makes the system applicable for biomedical applications
such as photodynamic therapy.
BioMolecular Nanotechnology
The BioMolecular Nanotechnology (BNT) group is founded in 2009 by the appointment
of it’s chair prof. Jeroen Cornelissen and acts on the interface of biology, physics
and materials science coming from a strong chemical back ground. The research of
the group centers around the use of biomolecules as building blocks for (functional)
nanostructures, relying on principles from Supramolecular and Macromolecular
Chemistry. Current research lines involve the use of well-defined nanometer-sized
protein cages as reactors and as scaffolds for new materials, while new directions in
the field of liquid crystalline materials are explored. The success of the multidisciplinary
work of the group partly relies on intense interactions within MESA+ and with other
(inter)national collaborators.
Figure: Schematic representation of the encapsulation of Pc
stacks into CCMV VLPs. The length and arrangement of the
stacks within the capsids in the cartoon are tentative.
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Prof. dr. Wim J. Briels“There's plenty of room in the middle.”
Is it possible for flat clathrin lattices to transform into cages?
Clathrin is a three-legged protein with the ability to self-assemble into a large variety of polyhedral cages. The nucleation and
growth of a curved lattice against the inside of a cell membrane wraps the membrane around a cargo at the opposite side of the
membrane, thereby creating a cargo-laden vesicle inside the cell (endocytosis). Completed cages contain exactly twelve pentagons
and a variable number of hexagons. We have developed a highly coarse-grained simulation model of this protein, see Figure 1, and
thereby determined the crucial features enabling self-assembly. Cryo-electron microscopy images (cryo-EM) show that clathrin also
self-assembles into flat hexagonal lattices adjacent to a membrane. A long-standing conundrum in the field is whether and how a
flat ‘plaque’ transforms into a cage, the main problem being that the introduction of twelve pentagons requires a daunting amount of
reshuffling of the lattice. Our simulations reveal a much simpler mechanism: when the flat triskelia in a plaque acquire a small pucker,
e.g. in response to the presence of cargo, the resulting build-up of stresses causes the lattice to fracture and release a dome-like
fragment. This nucleus subsequently grows into a cage by binding free clathrin from the cytosol, with the obligatory twelve pentagons
easily being created at the lattice edge. Numerous cryo-EM images show hemi-spherical clathrin domes partially surrounded by
semi-circular frayed lattice edges, remarkably similar to our simulation snapshots, which hitherto were overlooked as transition
intermediates. The novel mechanism also explains why multiple coats often appear to originate from the same ‘hot spot’.
HIGHLIGHTED PUBLICATION: W.K. den Otter, W.J. Briels, The generation of curved clathrin coats from flat plaques, Traffic 12 (2011) 1407-1416.
Computational bioPhysics
The Computational BioPhysics (CBP) group investigates how the thermo-
dynamic and rheological properties of a complex fluid emerge from its
molecular constitution. Our computational studies focus on the mesoscopic
level, i.e. the time and length scales of the macro-molecules determining
the macroscopic behaviour, while the atomic details of these molecules
are reduced to their bare essentials. By developing equations of motions
and force fields that capture only the crucial molecular features, a complex
molecule like a polymer or a protein can be modeled as a single particle.
This approach proves very successful in studying the emerging macroscopic
properties of biological and non-biological soft condensed matter.
Figure 2: Snapshot of colloidal particles in a sheared non-
Newtonian fluid, made possible by the in-house development of
Responsive Particle Dynamics. The simulations are producing
new insights into the unexplained phenomenon that some visco-
elastic fluids induce alignment of colloids under shear, with
the arrows indicating the flow direction, while other fluids with
superficially similar flow properties leave the colloids randomly
distributed.
Figure 1: Simulations have uncovered the prerequisites that
allow clathrin proteins to self-assemble into a wide variety of
polyhedral cages.
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Figure: A single layer of graphene (Gr) separated from a copper
electrode (Cu) by three layers of hexagonal boron nitride (BN).
The dipole layers are visible as negative (blue) and positive (red)
charge contours.
Prof. dr. Paul J. Kelly”Computational Materials Science:
taking the guesswork out of
NanoScience and Technology.”
Understanding the magnetic, optical, electrical and structural properties
of solids in terms of their chemical composition and atomic structure by
numerically solving the quantum mechanical equations describing the motion
of the electrons is the central research activity of the group Computational
Materials Science (CMS). These equations contain no input from experiment
other than the fundamental physical constants, making it possible to analyze
the properties of systems which are difficult to characterize experimentally or
to predict the physical properties of materials which have not yet been made.
This is especially important when experimentalists attempt to make hybrid
structures approaching the nanoscale.
HIGHLIGHTED PUBLICATION: M. Bokdam, P.A. Khomyakov, G. Brocks, Z.C. Zhong, P.J. Kelly, Electrostatic Doping of Graphene through Ultrathin Hexagonal Boron Nitride
Films, Nano Letters 11 (2011) 4631-4635.
Ultrathin gate dielectric for graphene
The performance of silicon-based technology could be improved for almost half a century by making devices smaller and smaller.
Because this approach will eventually come up against the intrinsic limitations of silicon, there is a constant search for alternatives.
A material that has received much attention recently is graphene, a monolayer of graphite. Graphene is a two dimensional half metal
comprising sp2-bonded carbon atoms arranged in a honeycomb structure. The high mobility of both electrons and holes in graphene
makes it a promising starting material for high frequency transistors. For practical applications of such a material only one atom thick,
the choice of a suitable substrate is non-trivial. Hexagonal boron nitride (h-BN) is a completely flat layered material with the same
honeycomb structure as graphene with strong in-plane and weak out-of-plane interactions. Unlike graphene, it has a very large band
gap so it is an ideal substrate and gate dielectric with which to build metal|h-BN|graphene field-effect devices.
We used first-principles density functional theory (DFT) calculations for Cu|h-BN|graphene stacks to study how the position of the
Fermi level in graphene depends on the thickness of the h-BN layer and on a potential difference applied between Cu and graphene.
We developed an analytical model that describes this doping very well, allowing us to identify the key parameters that govern the
device behaviour. For ultrathin layers of h-BN, we predict an intrinsic doping of graphene that should be observable in experiment.
It is dominated by novel interface terms that were evaluated from DFT calculations for the individual materials and for interfaces
between h-BN and Cu or graphene.
Computational Materials Science
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No permission for emission
COPS scientists have experimentally demonstrated a prediction made nearly a quarter-century ago: that spontaneous emission of light
can be inhibited within a 3-D photonic bandgap. By learning how to control such emission and suppression, researchers could someday
build better solid-state lasers or reduce the inevitable noise in quantum computers.
To this end, the group developed “inverse woodpile” photonic band gap crystals with a 3-D diamond structure, in collaboration with
ASML, Philips, TNO. The crystals were etched out of silicon with nanometre precision utilizing a fully CMOS-compatible process - in
itself a remarkable, pioneering achievement. They calculated the theoretical band gap where all modes of light waves are forbidden in
all 3 dimensions - the photonic band gap.
Next, the researchers immersed the crystal into a suspension of colloidal quantum dots made of lead sulfide, which emit at photon
energies of 0.8 to 0.9 eV at room temperature, corresponding to telecommunications wavelengths (1,500 to 1,390 nm). The team excited
the quantum dots with short pulses from a 532-nm-wavelength laser. The excited dots act as single-photon sources. Because the
quantum-dot emission was relatively low, the scientists had to collect the light for hours and carefully subtract background noise.
As predicted, the decay rates of the quantum dot emissions within the photonic bandgap were reduced by a factor of 10, while they
were enhanced by as much as a factor of two outside the bandgap. In other words, it took the dots 10 times longer to emit a photon
within the crystal. In an actual finite-sized photonic band gap crystal, the strength of the effect depends on the distance of the dots
from the surface of the crystal.
The results build on theoretical studies of cavity quantum electrodynamics begun by American and Canadian scientists in the 1980s.
In parallel to the spontaneous emission work, COPS has also obtained a great success in realizing a record-high resolution optical focus
by using a so-called high-index resolution enhancement by scattering (HIRES).
Prof. dr. Willem l. Vos“COPS strives to catch light with
nanostructures. But beware dear
colleagues, since Shakespeare once
said: ‘Light, seeking light, doth light of
light beguile’. In other words: the eye in
seeking truth deprives itself of vision.”
Complex Photonic Systems
The Complex Photonic Systems (COPS) group studies light propagation in ordered
and disordered nanophotonic materials. We investigate photonic bandgap materials,
random lasers, diffusion and Anderson localization of light. We have recently
pioneered the control of spontaneous emission in photonic bandgaps and the active
control of the propagation of light in disordered photonic materials. Novel photonic
nanostructures are fabricated and characterized in the MESA+ cleanroom. Optical
experiments are an essential aspect of our research, which COPS combines with a
theoretical understanding of the properties of light. Our curiosity driven research
is of interest to various industrial partners, and to applications in medical and
biophysical imaging.
HIGHLIGHTED PUBLICATIONS: [1] M.D. Leistikow, A.P. Mosk, E. Yeganegi, S.R. Huisman, A. Lagendijk, W.L. Vos, Inhibited spontaneous emission of quantum dots observed
in a 3D photonic band gap, Phys. Rev. Lett. 107 (2011) 193903: 1-5. [2] E.G. van Putten, D. Akbulut, J. Bertolotti, W.L. Vos, A. Lagendijk, A.P. Mosk, Scattering Lens Resolves
sub-100 nm Structures with Visible Light, Phys. Rev. Lett. 106 (2011) 193905: 1-4.
Figure 1: Electron microscope image of a three-dimensional
diamond structure in silicon (encircled), consisting of identical
pores in an orthogonal pattern that cross each other at an angle
of 90º. The upper part of the figure shows the upper surface
of the chip, in which many pores have been etched. Top left a
dust particle can be seen that ended up on the crystal after the
process. In the side of the chip an orthogonal pattern of pores has
been etched in a single go, perpendicular to the other pores. The
scale at the top right is two micrometres, about 50 times as thin
as a human hair.
Figure 2: The graph shows when quantum dot light sources in
a photonic crystal emit light after being excited by a short laser
pulse at time 0 (blue triangles). The slope of the curves is inversely
proportional to the lifetime: the shallower the curve, the longer
the lifetime of the quantum dots. For comparison, dots outside
a crystal reveal a much shorter lifetime. The 10x longer lifetime
in the crystal is a measure for the strong inhibition of vacuum
fluctuations by the photonic band gap crystal.
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HIGHLIGHTED PUBLICATIONS: [1] D.B. Thakur, R.M. Tiggelaar, T.M.C. Hoang, J.G.E. Gardeniers, L. Lefferts, K. Seshan, Ruthenium catalyst on carbon nanofiber support layers
for use in silicon-based structured microreactors, Part I: Preparation and characterization, Applied catalysis B: environmental 102(1-2) (2011) 232-242. [2] D.B. Thakur, Y. Weber,
R.M. Tiggelaar, J.G.E. Gardeniers, L. Lefferts, K. Seshan, Ruthenium catalysts on Carbon Nano Fiber support layers for S-based structured microreactors I - Catalytic reduction of
bromate in aqueous phase, Applied catalysis B: environmental 102(1-2) (2011) 243-250.
Prof. dr. ir. Leon Lefferts“One of the most valuable
applications of nanotechnology
is in the area of heterogeneous
catalysis. The challenges are to
improve the level of control over the
active nanoparticles as well as the
local conditions at those particles,
and to understand the molecular
mechanism at the surface.”
Carbon-nano-fibers in microchannels: an advanced catalyst support for operation in liquid phase
Interdisciplinary work performed by Vijay Thakur in cooperation with the MCS group resulted in two publications in one issue of
Applied Catal. B, Environmental, the leading journal in environmental catalysis. It was nicely demonstrated that manipulation of the
microstructure (Figure 1) of the catalysts support layer based on carbon-nano-fibers (Figure 2), inside the channel in a microreactor,
induced am important improvement in the transport of traces of bromate to the catalytic active site. This improvement results in
enhanced removal of bromate (BrO3-) in the sub ppm range in drinking water. Bromate is a safety problem in drinking water produced
in regions close to salty water, thus always containing traces of Br-, in combination with ozone treatment.
Catalytic Processes and Materials
The aim of the Catalytic Processes and Materials (CPM) group is to understand hetero geneous
catalysis by investigation of catalytic reactions and materials on a fundamental level in
combination with their application in practical processes. Our research focuses on three themes:
1. Sustainable processes for fuels and chemicals, like catalytic conversion of biomass to fuels.
2. Heterogeneous catalysis in liquid phase.
3. High yield selective oxidation.
The fundamental study of surface reactions in liquid phase requires the development of new
analysis techniques for which CPM is in the forefront of leading catalysis groups in the world.
Moreover, we explore preparation and application of new highly porous, micro-structured
support materials as well as micro-reactors and micro-fluidic devices, using the information
obtained from in-situ spectroscopy studies.
Figure 1: A schematic representation of reactant flow inside
micro-channel coated with a classical washcoat layer (left) versus
carbon nanofiber layer (right).
Figure 2: SEM images in top view (left) and cross-section of a
micro-channel filled with CNFs. The micro-channels contain Si
pillars to improve the attachment of the fibers to the wall.
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Opposites attract; can excitons lead to a dissipation-less energy transport?
In physics a crucial difference exists between fermions and bosons. The former are spin-½ particles such as electrons, and the latter
are particles with zero or integer spin, such as photons and ‘Cooper-pairs’ of two electrons. The most spectacular manifestation
of the difference between the two classes of particles is the fact that at a sufficiently low temperature a system of bosons can
become completely entangled into a macroscopic phase-coherent quantum state; a Bose-Einstein condensate. Superconductivity is a
consequence of this condensation of the bosonic Cooper-pairs.
In the still enigmatic high-Tc superconductors an additional aspect comes into play, namely the fact that also in the ‘normal state’
the charge transport is highly anomalous, and strongly influenced by mutual interactions between the charge carriers (‘electronic
correlations’). In the MESA+ ICE group, and in the frame of an NWO VICI grant, a study is carried out on the creation and possible
Bose-Einstein condensation of another type of bosonic particles in such correlated electron compounds, namely bound states of
electrons and holes (excitons). Experimental studies are performed on thin-film sandwiches comprised of p-doped and n-doped cuprate
perovskites, and in a collaboration with the Institute Lorentz in Leiden the consequences of a Bose-Einstein condensation of excitons
is studied theoretically. A particulary interesting question is whether such exciton condensation could provide an alternative pathway
to high(er) temperature superfluidity and perhaps even superconductivity, which both are of great interest for a dissipationless
transportation of energy.
The research has led to the prediction of a novel quantum effect, namely the quantization of magnetic flux enclosed in a ring-shaped
bilayer system (Fig. 1) as a crucial test to verify the occurrence of exciton Bose-Einstein condensation. Experimental research is
underway to test these predictions (Fig. 2).
HIGHLIGHTED PUBLICATION: L. Rademaker, J. Zaanen, H. Hilgenkamp, Prediction of quantization of magnetic flux in double-layer exciton superfluids, Phys. Rev. B. 83
(2011) 012504.
Prof. dr. ir. Hans Hilgenkamp"The Interfaces and Correlated Electron
systems group (ICE) focuses on materials
and interfaces with unconventional
electronic properties, especially related
to interactions between the mobile
charge carriers".
Interfaces and Correlated Electron systems
Materials with exceptional, well-tailored properties are at the heart of many new
applications. In the electronic/magnetic domains, powerful means to create such
properties are nanostructuring as well as the use of compounds in which the intrinsic
physics involves ‘special effects’. These can arise from intricate interactions of the
mobile charge carriers mutually and/or with the crystal lattice. In the Interfaces and
Correlated Electron systems group (ICE), the fabrication and basic properties of such
(nano-structured) novel materials are studied, and their potential for applications is
explored. Current research involves superconductors, p- and n-doped Mott compounds,
topological insulators, electronically active interfaces between oxide insulators and
novel electronic materials for energy harvesting applications.
Figure 2: Schematic of a concentric p-n ring structure to study
exciton formation in correlated electron systems and their
possible Bose-Einstein condensation, as fabricated using thin
film technologies in the MESA+ Institute.
Figure 1: Prediction of a novel quantum effect; the magnetic flux
in a concentric ring structure composed of an electron-doped
and hole-doped layers becomes quantized in the case of a Bose-
Einstein condensation of the indirect excitons formed between
these layers (Rademaker et al., PRB 2011).
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HIGHLIGHTED PUBLICATIONS: [1] Luiten-Olieman et al., Porous stainless steel hollow fibers with shrinkage-controlled small radial dimensions, Scripta Materialia 65 (2011) 25-28.
[2] Luiten-Olieman et al., Porous stainless steel hollow fiber membranes via dry-wet spinning, J Membrane Sci 370 (2011) 124-130. [3] Luiten-Olieman et al., Towards a generic
fabrication method of thin organic hollow fibers, submitted.
Prof. dr. ir. Arian Nijmeijer“Material science on the Ångstrom
scale to make ceramic membranes
that can be applied in large scale
separation processes”.
Porous inorganic hollow fibers with shrinkage-controlled small radial dimensions
The Inorganic Membranes group has developed a facile method for inexpensive production of thin inorganic hollow fiber membranes,
with unprecedented small radial dimensions, superior thermal and chemical stability, and high mechanical strength. The method is
based on dry-wet spinning of a particle loaded polymer solution, followed by thermal treatment to burn out the polymer and sinter the
inorganic particles together. The extremely small radii (down to ~200 mm) are achieved by surface energy driven viscous deformation
of the fibers above the glass transition (Tg) of the polymer, prior to burn out of the polymer and sintering. During viscous deformation,
so-called macro-voids are removed from the fiber, causing extensive shrinkage and enhanced mechanical properties. Figure 1 depicts
schematically the change in morphology and dimensions of a stainless steel loaded fiber during heat treatment.
The method is applicable for a broad range of inorganic materials (see Figure 2), on the condition that the particle concentration is kept
within a powder specific limited concentration range. Above a certain maximum concentration the timescale of viscous deformation
becomes too large and removal of macro-voids is minor. Below a minimum particle concentration, particle cohesion during burn-out
of the polymer is insufficient to obtain strong and well-defined fibers. The results allow fabrication of inorganic membranes with
extremely large surface area to volume ratio that can be used in applications that involve high temperatures, high pressure, and
aggressive chemicals, i.e., where organic membranes fail due to limited stability.
inorganic Membranes
Activities of the group Inorganic Membranes (IM) revolve
around energy efficient molecular separation under
extreme conditions, for instance high temperature, elevated
pressures, and chemically demanding environments, using
inorganic membranes. The group combines Materials
Science in the nanometer range length scale with Process
Technology on macroscopic scale. Particular topics include
sol-gel derived nano-porous membranes, ultra-thin hybrid
membranes, dense ion conducting membranes, and
inorganic porous scaffolds.
Figure 1: Schematic depiction of the fabrication of a thin stainless
steel hollow fiber.
Figure 2: Selection of thin inorganic hollow fibers, on the right a
commercial alumina capillary for comparison.
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Hydrogen Generation from Photocatalytically Active Nanowires: Towards Multifunctional Nanowire Devices
Nanorods and nanowires have a high potential for utilization in a wide range of novel nanotechnological and biomedical applications.
For solar fuel applications, we developed a novel type of segmented nanowire with emergent photocatalytic property. The nanowire
is essentially a photo-electrochemical nanowire diode. When dispersed in methanol/water and exposed to UV light, it autonomously
catalyzes the conversion of methanol to hydrogen. The functionality of the nanowire is based on its axially segmented architecture,
which consists of a photoactive zinc oxide (ZnO) segment, and a metallic segment that are connected via a Schottky barrier. When
excitons are formed in the ZnO photoanode upon illumination, the formed electrons are transported to the Ag cathode, where they
participate in the reduction of aqueous protons to hydrogen gas. The electron holes remain behind in the ZnO phase and is eventually
consumed at the anode surface in the oxidation of methanol.
The modular approach to constructing multiply segmented nanowires is a versatile and flexible way to fabricate autonomously
functioning nanosystems that are able to carry out multiple complex tasks, e.g. autonomous movement, magnetic control over the
direction of movement, and photocatalytic activity.
HIGHLIGHTED PUBLICATION: A.W. Maijenburg, E.J.B. Rodijk, M.G. Maas, M. Enculescu, D.H.A. Blank, J.E. ten Elshof, Hydrogen Generation from Photocatalytic Silver|Zinc Oxide
Nanowires: Towards Multifunctional Multisegmented Nanowire Devices, Small 7 (2011) 2709-2713.
Prof. dr. ing. Dave H.A. Blank“The recent developments in controlled
synthesis and characterization tools has
increased the applicability of inorganic
nanoscale materials enormously.
This holds especially for complex and
functional oxide materials, enabling the
development of new materials and devices
with novel functionalities. Our aim is to
consolidate our leading role in this field.”
inorganic Materials Science
The Inorganic Materials Science (IMS) group works at the international forefront
of materials science research on complex metal oxides and hybrids, and
provides an environment where young researchers and students are stimulated
to excel. The research is focused on establishing a fundamental understanding
of the relationship between composition, structure and solid-state physical and
chemical properties of inorganic materials, especially oxides. Insights into these
relationships enable us to design new materials with improved and yet unknown
properties that are of interest for fundamental studies as well as for industrial
applications. With the possibility to design and construct artificial materials on
demand, new opportunities become available for novel device concepts.
Figure 1: Working principle of photoactive segmented Ag|ZnO
nanowire. UV radiation is absorbed by the ZnO segment, creating
an electron-hole pair. The electrons flow into the Ag phase and
are consumed in an electrochemical reduction process, forming
hydrogen gas. The hole in the ZnO segment is consumed in an
oxidative half-reaction, in this case the oxidation of methanol.
Figure 2: Scanning electron microscope image of a axially
segmented silver-zinc oxide nanowire. Nanowire length 4 μm;
diameter 150-200 nm.
Figure 1a: Optical measurement set-up of the spectral-domain
OCT system with a free-space Michelson interferometer and an
integrated optical AWG spectrometer.
Figure 1b:OCT image of a three-layered scattering phantom.
Figure 2: Raman spectra, measured on human teeth in two
orthogonal polarizations with an integrated optical spectrometer,
on (a) sound enamel, (b) early-stage caries.
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Prof. dr. Markus Pollnau“Guiding light into the
future!"
integrated optical spectrometers for biomedical sensing applications
Arrayed waveguide gratings (AWGs) are known as elegant and effective devices for optical wavelength separation. Significant
improvements in robustness, size, and cost of some biomedical instrumentation may be achieved by replacing the currently
used bulky spectrometers by AWGs. To employ these in such sensing applications, design trade-offs need to be made, involving
wavelength range, cross-talk, polarization sensitivity, and efficiency of signal collection.
We developed AWGs for two biomedical applications: optical coherence tomography (OCT) for cross-sectional imaging of, e.g., the
eye or the skin [1], and Raman spectrometry, in this case for quality assessment of tooth enamel [2].
Figure 1a schematically shows a so-called spectral-domain OCT set-up. Back-reflected light from (sub-surface) structures in an
object interferes with light directly from a broad-band light source. The resulting interference pattern depends on both the depth
of the reflective structure and the wavelength. By spectrally analysing this pattern, the depth structure can be reconstructed, as
shown for a layered “phantom” object in Figure 1b.
Raman spectroscopy can provide information on the chemical composition of an object, by measuring the wavelength shift of
light due to the vibrational energy of specific chemical bonds. Early-stage dental caries is inconspicuous to the naked eye, but
the chemical and structural change is readily visible in the Raman spectrum. Two polarization components of a dental Raman
spectrum are measured with an AWG. The quality of enamel affects the ratio between these components, as shown in the measured
spectra of Figure 2.
As the intensity of a Raman spectrum is typically a billion times smaller than that of the light source, efficient collection of the
scattered light is of utmost importance. To this end, we have exploited the imaging properties of AWGs to provide an integrated
confocal light delivery and signal collection system [3], that can be readily integrated with the spectrometer.
Integrated Optical MicroSystems
The Integrated Optical MicroSystems (IOMS) group performs research on highly compact,
potentially low-cost and mass-producible optical waveguide devices with novel functionalities.
After careful design using dedicated computational tools, optical chips are realized in
the MESA+ clean-room facilities by standard lithographic tools as well as high-resolution
techniques for nano-structuring, such as focused ion beam milling and laser interference
lithography. Integrated optical devices, including on-chip integrated light sources and
amplifiers, optically resonant structures, micro-mechanically or thermo-optically actuated
switches, spectrometers, and novel light generation, manipulation, and detection schemes
based on these devices are developed for a variety of applications in the fields of optical
sensing, bio-medical diagnostics, and optical communication.
HIGHLIGHTED PUBLICATIONS: [1] B.I. Akca, V.D. Nguyen, J. Kalkman, N. Ismail, G. Sengo, F. Sun, A. Driessen, T.G. van Leeuwen, M. Pollnau, K. Wörhoff, R.M. de Ridder, Towards spectral-domain
optical coherence tomography on a chip, IEEE J. Select. Top. Quantum Electron. 18 (2012) 1223-1233. [2] N. Ismail, L.-P. Choo-Smith, K. Wörhoff, A. Driessen, A. C. Baclig, P. J. Caspers, G. J. Puppels,
R. M. de Ridder, M. Pollnau, Raman spectroscopy with an integrated arrayed-waveguide grating, Opt. Lett. 36 (2011) 4629-4631. [3] N. Ismail, B. I. Akca, F. Sun, K. Wörhoff, R. M. de Ridder, M.
Pollnau, A. Driessen, Integrated approach to laser delivery and confocal signal detection, Opt. Lett. 35 (2010) 2741-2743.
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Figure 1: Schematic of the ellipsometer setup.
Figure 2: Environmentally induced polarization variation of light
from an optical fiber shows as a random walk of the Stokes
polarization vector on the Poincare sphere, but remains bound
to a well-defined orbit (left). An ellipsometric characterization
of thin films is then obtained with sub-nanometer precision
by measuring the tilt or deformation of such orbits, see e.g.
projection on S(3)-S(4) plane (right). Measured orbits are shown
for light exiting the fiber (green), for reflection on a multilayer
mirror [black] and on carbon films of 0.3 nm [red] and 0.8 nm
[blue] on top of the multilayer mirror.
Prof. dr. Klaus J. boller"Light displays the
beauty of nature.
We put light to work,
for knowledge and
applications."
ellipsometry with an undetermined polarization state
Polarization-based measurements become increasingly important, both as a fundamental tool for scientific research, and as a vital
tool for applications in the chemical, food, and pharmaceutical industries. In surface science, it is well known that polarization
based measurements are extremely sensitive when the polarization of light incident to the sample can be set and detected with high
accuracy. An example of this is ellipsometry which can measure sub-monolayer changes in surface coverage. However, it was believed
that ellipsometry with such precision was not possible in a remote mode using fiber-transmitted light, because fibers suffer from
environmentally induced, unpredictable instabilities of their birefringence that results in a randomly varying output polarization state.
We show that, in spite of this randomness, ellipsometry can be performed in a fiber based setup (see Figure 1 [3]), by actually exploiting
the randomness. We demonstrate, using a polarization maintaining fiber, that the polarization output state, though undergoing random
changes, still remains restricted to a sharply defined orbit on the Poincaré polarization sphere (see Figure 2 left). Once this orbit is
mapped out through random walk of the polarization, the effect of the sample on the reflected light shows up as a tilt or deformation
of the orbit (see Figure 2). These changes allow retrieval of the ellipsometric parameters and . Using this novel approach, we
demonstrated that the sensitivity is again as high as required for the detection of monolayer films on surfaces.
Laser Physics and Nonlinear Optics
The Laser Physics and Nonlinear Optics (LPNO) group explores the generation and manipulation
of coherent light in improved and novel ways. This included new concepts for lasers and nonlinear
optical interactions. Research comprises wide ranges of intensities, time scales and light
frequencies. Regarding laser concepts we investigate a novel types of laser such as based on slow
light in photonic structures or based on phase-locked diode arrays. Nonlinear generation of light
with large spectral bandwidth is investigated [1], such as for sensitive and specific detection of
molecules. We devise methods to implement such nonlinear generation in waveguides for use in
integrated photonics. Nonlinear generation at extreme intensities is investigated, such as to generate
ultra-short pulses in the XUV wavelength range. Such radiation in combination with nano-structured
optics can enable improved spectral control [2], microscopy and XUV lithography on the nano-scale.
HIGHLIGHTED PUBLICATIONS: [1] J. Storteboom, C.J. Lee, A.F. Nieuwenhuis, I.D. Lindsay, K.-J. Boller, Incoherently pumped continuous wave optical parametric oscillator
broadened by non-collinear phasematching, Opt. Express 19 (2011) 21786. [2] I.V. Kozhevnikov, R. van der Meer, H.M.J. Bastiaens, K.-J. Boller, F. Bijkerk, Analytic theory of
soft x-ray diffraction by lamellar multilayer gratings, Opt. Express 19 (2011) 9172. [3] F. Liu, C.J. Lee, J. Chen, E. Louis, P. J. M. van der Slot, K.-J. Boller, F. Bijkerk, Ellipsometry
with randomly varying polarization states, Opt. Express 20 (2012) 870.
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LC chips with 1 million theoretical plates
To cope with the ever increasing sample complexity, in particular in the Life Sciences (metabolomics, proteomics, etc.), analytical
instruments, like liquid chromatography (LC) systems, have continuously been improved in order to achieve higher separation
efficiencies. One relatively simple way to create a high efficiency in regular (one dimensional) LC is to fabricate very long separation
columns. This has indeed been done by several research teams, using columns of tens of meters long packed with particles of 5 µm
diameter or larger, which can result in efficiencies of hundreds of thousands of plates but with the obvious drawbacks of very long
separation times and the need for very high pressures. The best results were obtained for a set of coupled monolithic columns (which
have higher permeability than packed columns) with a total length of 12 m, giving 1.2 million plates in 2.5 hours, at quite common
pressures of 400-500 bars.
In collaboration with the Vrije Universiteit of Brussels, chromatographic column chips with micromachined pillar arrays columns have
been continuously improved over the last decade. Pillar array columns are a powerful alternative for classical packed bed columns and
monoliths, because the perfect order of pillar arrays improves (i.e. decreases) the plate height, which is the characteristic parameter
describing the performance of an LC column, by a factor of 2 or more compared to a column packed with particles of similar size as
the pillars, as we have demonstrated in previous work (PhD thesis of Wim De Malsche, 2008).
An essential additional contribution to the improvement of LC chips was the design and microfabrication of flow distributors at the
inlet and outlet of pillar array columns. The optimized flow distributor allows the connection of a pillar array column to conventional
commercial chromatographic instrumentation (injectors and detectors) with a minimal effect of separation efficiency.
Combining sections of pillar array columns (pillar diameter: 5 µm) connected via optimized flow distributors to low-dispersion bends
(Figure 1), it was possible to fold a 3 m LC column on a fraction of a 10 cm diameter silicon wafer (Figure 2). With this chip, 1 million
theoretical plates were achieved for an unretained marker, for a column pressure of 350 bar, within only 20 minutes, which is much
faster than what had been previously been achieved.
HIGHLIGHTED PUBLICATIONS: [1] J. Vangelooven, S. Schlautmann, F. Detobel, H. Gardeniers, G. Desmet, Experimental optimization of flow distributors for pressure-driven
separations and reactions in flat-rectangular microchannels, Anal. Chem. 83 (2011) 467-477. [2] W. De Malsche, J. Op De Beeck, S. De Bruyne, H. Gardeniers, G. Desmet, The
realization of 1,000,000 theoretical plates in liquid chromatography using very long pillar array columns, Anal. Chem. 84 (2012) 1214-1219.
Prof. dr. Han J.G.e. Gardeniers"Downscaling and integration of unit
operations in chemistry is exploited to
enhance yield and selectivity of chemical
reactions and product purification, and to
improve the analysis of mass-limited (bio)
chemical samples. Furthermore, micro and
nanostructured surfaces with integrated
fluidic and electronic functionality are used in
the study of living cell and tissue behavior."
Mesoscale Chemical Systems
The research focus of the Mesoscale Chemical Systems (MCS) group is on the themes:
n Alternative activation mechanisms for chemical process control and process
intensification: Examples are: electrostatic control of surface processes and reactions
in liquids, photochemical mciroreactors for solar-to-fuel conversion, sonochemical
microreactors and microreactors with integrated work-up functionality;
n Miniaturization of chemical analysis systems: Examples are: liquid chromatography
on a chip, microscale NMR, nanostructured gas sensors, micro optical absorption
cells (UV, IR); n Micro and nanostructured surfaces for biological studies: Chip-
based array of bioreactors with integrated electronic and microfluidic functionality
are developed for the study of neurophysiologic responses of neuronal tissue.
Figure 1: Column sections with circular pillars with a diameter
of 5 μm, connected via flow distributors and a low dispersion
microchannel bend. The arrows indicate the direction of liquid
flow.
Figure 2: Photograph of 3 m long pillar array column on a
silicon chip, with connecting capillaries and fittings.
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HIGHLIGHTED PUBLICATION: A. Perl, A. Gomez-Casado, D. Thompson, H.H. Dam, P. Jonkheijm, D.N. Reinhoudt, J. Huskens, Gradient-driven motion of multivalent ligand
molecules along a surface functionalized with multiple receptors, Nature Chemistry 3 (2011) 317-322.
Prof. dr. ir. Jurriaan Huskens"Molecular
nanoFabrication:
assembling the future of
molecular matter!"
A hop, skip and jump
The kinetics of multivalent (multi-site) interactions at interfaces is poorly understood despite its fundamental importance for molecular
or biomolecular motion and molecular recognition events at biological interfaces (membranes).
In a recent study published in Nature Chemistry, we have used fluorescence microscopy to monitor the spreading of mono-, di- and
trivalent ligand molecules on a receptor-functionalized surface, and performed multi-scale computer simulations, in collaboration
with Dr. Damien Thompson from Tyndall, Cork, in order to understand the surface diffusion mechanisms.
Three mechanisms for multivalent surface diffusion were identified, which we dubbed walking, hopping and flying (Figure 1).
Fluorescent guest molecules were printed in stripe patterns on receptor surfaces, and incubated in solutions containing varying
concentrations of the same receptor, in order to induce competition and thus promote spreading (Figure 2). To our surprise, the
spreading rate as a function of receptor concentration showed a complex behavior, initially increasing in speed, then decreasing,
and increasing again. This could only be explained by assuming the coexistence of several spreading mechanisms (Figure 1).
Analogous to chemotaxis, we found that the spreading is directional – along a developing gradient of vacant receptor sites – and is
strongly dependent on ligand valency and on the concentration of a competing monovalent receptor in solution. The study shows
that the interfacial behavior of multivalent systems is much more complex than that of monovalent ones.
Molecular nanoFabrication
The Molecular nanoFabrication (MnF) group, headed by Prof. Jurriaan Huskens, focuses on nano-
chemistry and self-assembly. Key research elements are: supramolecular and monolayer chemistry
at interfaces, multivalency, supramolecular materials, biomolecule assembly and cell patterning,
nano particle assembly, soft and imprint lithography, chemistry in microfluidic devices, and multistep
integrated nanofabrication schemes. Application areas are: chemical and biosensing, tissue engineering,
heavy metal waste handling, catalysis and synthesis, solar-2-fuel devices, and nano-, spin- and flexible
electronic devices. The group has several collaborations within MESA+, e.g. on the assembly of proteins
and cells on patterned surfaces (with the TR group) and on nanoelectronic and spintronic devices (with
the NE group). Furthermore, the group actively participates in the Twente Graduate School program
Novel NanoMaterials, and in the national programs NanoNext and Towards BioSolar Cells.
Figure 1: Spreading of multivalent molecules on receptor
interfaces: cartoon of the elementary mechanisms involved in
multivalent surface diffusion.
Figure 2:
Left: Fluorescence microscopy images (top) and integrated line
profiles (bottom) of printed patterns of a divalent guest on a
receptor surface after incubation in a receptor-containing solution
for given amounts of time.
Right: Spreading rates as a function of the receptor concentration
in solution used for incubating the printed guest samples showing
the unexpected decrease in spreading rate for the multivalent
guests GII and GIII at intermediate receptor concentrations.
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Deformation induced pattern transformations in soft granular crystals
Ordered arrays of particles are excellent candidates for components of future acoustic, optical and electronic devices. The MSM
group studied, by experiments and numerical simulations, the compression of a two-dimensional regular array of millimeter scale
cylindrical particles with contrasting dimensions. Under uni-axial compression the system undergoes an intriguing transformation
to a new periodic pattern, as illustrated in figure 1. The transformation is smooth and homogeneous for particles with a size ratio of
0.53, and the original pattern is recovered after unloading. At a slightly larger size ratio of 0.61, compressions beyond a critical strain
induce a sudden transition, reminiscent of a shear band, to a pattern that no longer returns to the initial state upon unloading. The
simulations indicate that this qualitative difference is mainly determined by the size ratio of the particles, whereas their mechanical
properties are of lesser importance. Future research could be done towards nano-scale mechanical systems where also e.g. light will
be affected by the pattern transformation when the structures are of size of the wave-length of electromagnetic waves.
HIGHLIGHTED PUBLICATIONS: [1] F. Göncü, S. Willshaw, J. Shim, J. Cusack, S. Luding, T. Mullin, K. Bertoldi, Deformation induced pattern transformation in a soft granular
crystal, Soft Matter 7 (2011) 2321. [2] F. Göncü, S. Luding, K. Bertoldi, Exploiting pattern transformation to tune phononic band gaps in a two-dimensional granular crystal,
J. Acoust. Soc. Am. 6 (2012) EL475-EL480.
Prof. dr. stefan luding“How does contact mechanics at the particle
level determine the macroscopic flow
properties of granular matter?”
Multi Scale Mechanics
The group Multi Scale Mechanics (MSM) studies fluids and solids, as well
as granular systems where various physical phenomena with different
characteristic time- and length-scales are taking place simultaneously. At each
length scale, the question arises how the mechanics at that level is determined
by the properties of the underlying level, and how, in turn, the current level
affects the next level. Micro-Macro theory is one way to predict and describe this
hierarchy, and advanced numerical simulations help us understand the various
levels and their couplings. By combining numerical simulations with theory
and experiments, the Multi Scale Mechanics group aims at understanding the
properties of granular and related advanced materials.
Figure 1: Uni-axial compression induces a pattern
transformation in a two-dimensional regular array of particles
with contrasting dimensions and softness. Here, the original
state is recovered upon unloading.
Figure 2: Snapshot of a simulation box containing 125,000
particles with a very wide distribution of radii. By developing an
efficient algorithm to detect contacts in extremely polydisperse
systems, we are now able to calculate the equations of state,
jamming transition densities, and structural slow changes like
nucleation for these systems.
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Dr. ir. Kitty nijmeijer“Molecular design of membranes
to control mass transport.”
Pushing the limits of block copolymer membranes for co2 separation
This paper presents an integrated concept for the design of PEO based block copolymer membranes as a method to increase the
CO2 permeability while maintaining the CO2/N2 selectivity. It combines the enhancing effect on the permeability of tailoring the
molecular design of the block copolymers with that of molecular blending. The current work describes the synthesis and mass
transport properties of a series of such molecularly tailored PEO based membranes and a poly(ethylene glycol) based additive. PEO-
ran-PPO5000-T6T6T/PDMS-PEG blend membranes (Figure 1) have been synthesized and their pure gas permeation characteristics have
been analyzed. The addition of the PDMS-PEG additive results in exceptionally high CO2 permeable block copolymer membranes. At
50 wt.% additive content, a CO2 permeability as high as 896 Barrer has been obtained, at sufficiently high CO2/light gas selectivities.
The performance of this system (and potential other systems) exceeds the boundaries (described by Robeson) that existed until
recently (Figure 2). This shows that by smart design and selection of the molecular structure of the membrane, the performance of
membranes can be increased to a level formerly unknown for this type of block copolymers. The concept presented is not limited to
this specific case and hence opens a window of opportunity for further development of highly permeable block copolymer systems
for CO2 separation and in particular for use in post-combustion CO2 capture.
Membrane Science and Technology
The research group Membrane Science & Technology
(MST) focuses on the multi-disciplinary topic of membrane
science and technology for the separation of molecular
mixtures. We aim at designing polymer membrane
chemistry, morphology and structure on a molecular
level to control mass transport phenomena. We consider
our expertise to be a multidisciplinary knowledge chain
ranging from molecule to process. The research program
is divided into three application clusters: Energy, Water
and Life Sciences.
HIGHLIGHTED PUBLICATION: S.R. Reijerkerk, M. Wessling, K. Nijmeijer, Pushing the limits of block copolymer membranes for CO2 separation, Journal of Membrane
Science 378 (1-2) (2011) 479-484.
CH2 CH2 O CH2 CH Ox
y C
O
C
O
O CH2 CH2 O CH2 CH Ox
y
n
CH3CH3
(a)
C N
O
(CH2)6 N CCN(CH2)6N
O
C
O
C O
OO
CO
O
HHHH
(b)
Si O Si OCH3
CH3
CH3
CH3
CH3
Si O SiCH3
CH3
CH3
OO
CH3p
m
n
CH3
(c)
Figure 1: Chemical structure of (a) the PEO-ran-PPO5000 soft
segment, (b) the T6T6T hard segment and (c) the PDMS-PEG
additive (80 wt.% PEG).
Figure 2: Robeson CO2/N2 upper bound relationship at 35°C. The
data obtained in the current work for blends of the PEO-ran-
PPO5000-T6T6T block copolymer and the PDMS-PEG additive (n)
are compared to work in literature.
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Polymeric Coatings for Luminscent Nanocrystals
Quantum Dots (QD) are semiconducting nanocrystals that show strong, nearly monochromatic optical fluorescence emission. The
color of this emission can be tuned by changing the size of the nanocrystal. The stable and strong fluorescence, and the tunability
of the color make these QDs interesting candidates as optical markers in biological and biomedical research. A protocol describing
a new class of polymeric coating (Figure 1) for QDs was developed by the Materials Science and Technology group in collaboration
with researchers from Singapore. The method described in the protocol is based on functionalization of an anhydride polymer
backbone with nucleophilic agents. Small functional groups, bulky cyclic compounds and polymeric chains can be integrated with
the coating prior to solubilization. The polymer-coated QDs display good colloidal stability in water, which is sufficient for many
proposed applications, such as in cell imaging. They furthermore can be covalently coupled to other structures thus allowing one to
integrate them in hierarchical, functional materials. To demonstrate bio-labelling applications, the team carried out cell imaging of
the mammalian cancer cells C-6 (see image).
HIGHLIGHTED PUBLICATION: D. Janczewski, N. Tomczak, M.-Y. Han, G.J. Vancso, Synthesis of functionalized amphiphilic polymers for coating quantum dots, Nature
Protocols 6 (2011) 1546-1553.
Prof. dr. G. Julius Vancso "The general focus of research in the MTP
group revolves around devising and building
tools and synthesizing molecular platforms
that enable studies of macromolecular
structure and behavior from the nanometer
length scale, bottom up. This knowledge is
then used in macromolecular materials and
devices with enhanced or novel properties
and functions for targeted applications."
Materials Science and Technology of Polymers
The current research in the Materials Science and Technology of Polymers (MTP) group
focuses on platform level research in macromolecular nanotechnology and polymer materials
chemistry. The applications are utilized in collaborations with specialized groups. The
projects target problems aiming at controlled synthesis of stimulus responsive “intelligent”
polymers, and manipulation as well as fabrication of complex polymeric architectures in
combination with nanoparticles, and metallic or semiconductor nanocrystals. Controlled
assembly of systems from the nanoscale to macroscopic dimensions, and their applications
in surface engineering, responsive molecular architectures, devices such as molecular
motors, sensors and actuators, nanostructured composites, and molecular delivery are
considered. The development of enabling tools such as scanning probe microscopes, and
optical approaches, including single molecule imaging, complements this effort.
Figure 2: Image of mammalian cancer cells marked with red
light-emitting QDs. The blue color is emitted by the stained cell
nuclei.
Figure 1: Generic structure of the coating polymer. (R is a
functional group, which can show chemical reactivity)
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Prof. dr. ir. Jaap J.W. van der Vegt“Without Mathematics there
will be no significant advances in
Computational Science.”
a novel numerical method for multi-fluid flow computations
Multi-fluid problems, such as droplets in inkjet printing and gas bubbles in small micro devices require the accurate capturing of the
liquid-gas interface. Many numerical algorithms tend to diffuse the interface and do not capture the details of the complex dynamics
at the interface, such as instabilities and the break-up and coalescence of the interface. We developed a novel numerical method for
multi-fluid computations by combining a space–time discontinuous Galerkin finite element discretization of the multi-fluid equations
with a level set method and cut-cell based interface tracking. The space–time discontinuous Galerkin method offers high accuracy,
an inherent ability to handle discontinuities and a very local stencil, making it relatively easy to combine with local mesh refinement
to capture flow details near the interface. The front tracking is incorporated via cut-cell mesh refinement to ensure a sharp interface
between the fluids. To compute the interface dynamics the level set method is used because of its ability to deal with merging and
breakup. Also, the level set method is easy to apply in higher dimensions. Small cells arising from the cut-cell refinement are merged
to improve the stability and performance. The interface conditions are incorporated in the numerical discretization for the interface
and the space-time discontinuous Galerkin discretization ensures that the scheme is conservative as long as the numerical fluxes
are conservative. The numerical method is demonstrated on a helium bubble in a tube filled with air modeled with the compressible
Euler equations. A shock wave causes a Rayleigh-Taylor instability at the helium-air interface which is accurately modeled by the
numerical algorithm.
Mathematics of Computational Science
The Mathematics of Computational Science (MaCS) group focuses on the mathematical
aspects of advanced scientific computing. The two main research areas are the
development, analysis and application of numerical algorithms for the (adaptive) solution
of partial differential equations and the mathematical modeling of multi-scale problems
making these accessible for computation. Special emphasis is put on the development
of discontinuous Galerkin finite element methods, efficient (parallel) solution algorithms,
and the modeling of complex turbulent flows using Large Eddy Simulation. Important
applications are in the fields of (dispersed) two-phase and granular flows, turbulent flows
(including particles, combustion, rotation and buoyancy), free surface flows, energy
systems, bio-fluid mechanics and computational electromagnetics.
HIGHLIGHTED PUBLICATION: W.E.H. Sollie, O. Bokhove, J.J.W. van der Vegt, Space-time discontinuous Galerkin finite element method for two-fluid flows, Journal of
Computational Physics, 230 (2011) 789-817.
Figure: Density contours of helium bubble-air shock interaction
test using a space-time discontinuous Galerkin finite element
method with a combined cut-cell level set approach.
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Unraveling the mechanisms of -Synuclein oligomer-membrane interactions
-Synuclein is a small intrinsically disordered protein that is abundantly expressed throughout the human brain. Aggregation of
this protein is implicated in the onset and progression of Parkinson’s disease, and there is compelling evidence that the interaction
of small oligomeric aggregates of the proteins with lipid membranes contributes to neurotoxicity. Using an assay based on the
bleaching of fluorescent lipids, postdoctoral fellow Dr. Martin Stöckl has recently shown that -synuclein oligomer-induced impairment
of membrane integrity is not limited to the formation of permanent membrane spanning pores. Using lipid mixtures with a varying
fraction of negatively charged lipids, a sharp cutoff where the impairment of membrane integrity sets in was observed, suggesting
that only membranes with an initial destabilization are susceptible. Detailed studies reveal an additional mechanism attributed to an
enhanced lipid flip-flop which has been observed for the first time. These findings indicate that an important mechanism for amyloid
oligomer toxicity lies in the disruption of lipid packing in the membrane.
Atomic force microscopy: probing frequency-dependent elasticity properties at the nanoscale
We have also studied amyloid fibrils of -Synuclein, which are typically several micrometers in length and 3 to 8 nm in diameter. Using
newly developed nanomechanical property mapping methods, such as Pulsed Force Microscopy (PFM), Harmonic Force Microscopy
(HarmoniX) and PeakForce QNM, it is possible with AFM to determine the elastic properties of these protein fibrils on the nanoscale.
Interestingly, all the modes mentioned above operate at a different frequency, and one of the outstanding questions is whether the
operating frequency influences the measured elastic modulus of the material. Kim Sweers, a PhD student who graduated in May
2012, used Pulsed Force Microscopy (PFM) and nano-indentation to mechanically characterize a sample consisting of low-density
polyethylene (LDPE, E=0.2 GPa) islands in polystyrene (PS, E=2 GPa). The material’s stiffness did indeed increase significantly with
an increasing frequency, and as a result of this also the apparent height of the PS phase.
HIGHLIGHTED PUBLICATIONS: [1] M.T. Stöckl, M.M.A.E. Claessens, V. Subramaniam, Kinetic measurements give new insights into lipid membrane permeabilization by
-synuclein oligomers, Mol. BioSyst. 8 (2012) 338-345. [2] K.K.M. Sweers, K.O. van der Werf, M.L. Bennink, V. Subramaniam, Spatially resolved frequency-dependent
elasticity measured with pulsed force microscopy and nanoindentation, Nanoscale (2012) 2072-2077.
Prof. dr. Vinod Subramaniam“Our goal is to perform
world-class research in
molecular and cellular
biophysics at the nanometer
scale, to gain new
insights into fundamental
mechanisms related to
disease.”
nanobiophysics
The Nanobiophysics (NBP) group is focusing on research in molecular and cellular biophysics at the
nanometer scale. We have intellectual interests in the mechanisms of neurodegenerative disease
related protein aggregation, in protein-ligand interactions on cell surfaces, and in the emerging field
of nanobiophotonics, where we use the toolbox of nanophotonics to manipulate biological fluorophores.
Nanoscale functional imaging, involving quantitative measurements of dynamic molecular and cellular
biophysical processes at high spatial, temporal, and chemical resolutions, is an integral element of
our research. We are also fascinated with developing cutting-edge technologies to address these
challenging research questions. Strong collaborations with other MESA+ groups and national and
international collaborators are essential elements of our work. We are closely involved in NanoNextNL,
as project leaders, and as programme director within the theme Nanomedicine.
Figure 1: Upon membrane binding -synuclein oligomers
integrate into the lipid bilayer of large unilamellar vesicles
(LUVs) where they form pore like structures or cause membrane
thinning. Using chemical bleaching of C6-NBD-PC by dithionite
we could not only observe a fast influx of dithionite but also
an additional slow loss of fluorescence presumably due to an
enhanced lipid flip-flop.
Figure 2: (a) Height and stiffness of low-density polyethylene
(LDPE) islands in a polystyrene (PS) surrounding, obtained with
Pulsed Force Microscopy. (b) Stiffness of LDPE as a function of
the probing frequency obtained with PFM (closed diamonds) and
nano-indentation (open circles).
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[HigHligHtS]Prof. dr. ir. Wilfred G. van der Wiel“Nanoelectronics
is where electrical
engineering,
physics, chemistry,
materials science
and nanotechnology
inevitably meet.”
Tunable doping of a metal with molecular spins
The mutual interaction of localized magnetic moments and their interplay with itinerant conduction electrons in a solid are
central to many phenomena in condensed-matter physics, including magnetic ordering and related many-body phenomena such
as the Kondo effect, the Ruderman–Kittel–Kasuya–Yoshida interaction and carrier-induced ferromagnetism in diluted magnetic
semiconductors. The strength and relative importance of these spin phenomena are determined by the magnitude and sign of the
exchange interaction between the localized magnetic moments and also by the mean distance between them. Detailed studies of
such systems require the ability to tune the mean distance between the localized magnetic moments, which is equivalent to being
able to control the concentration of magnetic impurities in the host material.
We have developed a conceptually novel approach for doping a non-magnetic metal film with localized magnetic moments that
involves depositing a monolayer of metal ligand complexes onto the film [1]. The metal ions in the complexes used are cobalt
and zinc, and the concentration of magnetic impurities in the gold film can be controlled by varying the relative amounts of
cobalt complexes (which carry a spin) and zinc complexes (which have zero spin). Kondo and weak localization measurements
demonstrate that the magnetic impurity concentration can be systematically varied up to ~800 ppm without any sign of inter-
impurity interaction (see Figure 1). The impurity concentration in the metal is directly proportional to the molecular spin dopant
concentration in solution (see Figure 2). Moreover, we find no evidence for the unwanted clustering that is often produced when
using alternative methods. This work should pave the way for the further study of the spin phenomena that lie at the very
heart of solid-state physics. The work was performed at MESA+ in a collaboration of the NanoElectronics (NE) and Molecular
nanoFabrication (MnF) groups.
nanoElectronics
The Chair NanoElectronics (NE) performs research and provides education in the field of nano-
electronics. Our research involves hybrid inorganic-organic electronics, spin electronics and
quantum electronics. The research goes above and beyond the boundaries of traditional disciplines,
synergetically combining aspects of Electrical Engineering, Physics, Chemistry, Materials Science,
and Nanotechnology. NE consists of more than 25 group members is actively looking for people to join.
The field of nanoelectronics comprises a mix of intriguing physical phenomena and revolutionary novel
concepts for devices and systems with improved performance and/or entirely new functionality.
NE has some dedicated infrastructure including MBE deposition, scanning tunneling microscopy,
cryogenic measurement systems down to temperatures of 10 mK in combination with magnetic fields
up to 10 tesla.
HIGHLIGHTED PUBLICATION: T. Gang, M. Deniz Yilmaz, D. Ataç, S.K. Bose, E. Strambini, A.H. Velders, M.P. de Jong, J. Huskens, W.G. van der Wiel, Tunable Doping of a
Metal with Molecular Spins, Nature Nanotechnology 7 (2012) 232.
Figure 2: Tunable molecular spin doping. Two different quantities
plotted as a function of Co complex fraction in the donor solution:
Magnetic impurity concentration, c, derived from Kondo
measurements (black squares); phase coherence length, l(2 K)
(blue dots), derived from weak localization measurements.
Figure 1: Kondo effect. a] Temperature dependence of the
normalized resistivity, norm(T)= (T)-min
xAu(150 K) of a
(99.99%) pure Au film (green hexagons), and the same Au film
with inserted molecular monolayers made from mixed Co
complex[x%]/Zn complex[(100-x)%] solutions with x = 0 (orange
diamonds), 25 (blue down triangles), 50 (green up triangles),
67 (red dots), and 100 (black squares). Inset: structure of metal
terpyridine complex, with “M” being either Co or Zn. b] Data of
(a) with the bare Au film curve subtracted. The solid curves are
fits to NRG theory for a S = ½ Kondo system. c] The experimental
data with both normalized temperature and resistivity values are
compared with numerical renormalization group (NRG) theory
for S =1/2, showing very good agreement.
p(15OK)-Pmin
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Metallic and insulating interfaces of amorphous srtio3-based oxide Heterostructures
A new type of conducting interfaces in complex oxide heterostructures based on strontium titanate has been created in
collaboration with researchers from the Technical University of Denmark.
The conductance confined at the interface of complex oxide heterostructures have been shown to provide new opportunities
to explore nanoelectronic as well as nanoionic devices. We have realized metallic interfaces in SrTiO3-based heterostructures
with various insulating overlayers of amorphous LaAlO3, SrTiO3, and yttria-stabilized zirconia films. The interfacial conductivity
results from the formation of oxygen vacancies near the interface, suggesting that the redox reactions on the surface of SrTiO3
substrates play an important role.
The result is important for understanding the origin of the metallic interface in epitaxial heterostructures, which is essentially a
quasi-2D electron gas between two insulating oxides, one of which is SrTiO3.
HIGHLIGHTED PUBLICATION: Y. Chen, N. Pryds, J.E. Kleibeuker, G. Koster, J. Sun, E. Stamate, B. Shen, G. Rijnders, S. Linderoth, Metallic and Insulating Interfaces of
Amorphous SrTiO3-Based Oxide Heterostructures, Nanoletters 11 (9) (2011) 3774-3778, doi: 10.1021/nl201821j.
Prof. dr. ing. Guus Rijnders"Recent advances in materials engineering at the
atomic scale facilitated a significant revival in the
field of functional complex oxide materials."
NanoElectronic Materials
The aim of the NanoElectronic Materials (NEM) group is to advance the field of
materials science, with a focus on nanomaterials for applications in electronic
devices. The research is based on current trends in nanomaterials science and
developments within MESA+, such as the controlled growth of materials, control
of their structure, and understanding of the structure-property relations. The
research is focused on three areas: Artificial Materials, Functional and Smart
Materials for Devices, as well as In-situ Characterization of Film Growth and
Interface Processes. These areas have in common that they find their basis in
materials science, bridging major disciplines within MESA+, i.e., Chemical
Engineering, Applied Physics, and Nanotechnology.
Figure 1: Top panel: High-resolution scanning transmission
electron microscopy image (cross section) of an atomically
sharp interface between amorphous LaAlO3 and crystalline
SrTiO3. Bottom panel: Electron energy loss spectroscopy
image, green=La, purple=Ti. (EMAT, Antwerp)
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Figure: (a) Cross-section image of an electrochemical nanogap
device. The spacing between the top and bottom electrode in this
device is 31 nm, allowing very fast shuttling of electrons between
the electrodes. (b) Measured current versus time for the top
(red) and bottom (black) electrodes. The plateaus in the current
correspond to 0, 1 or 2 molecule being present in the device at
any given time. The currents are equal but opposite because
each electron delivered to the top electrode is ejected from the
bottom electrode.
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a new single-molecule technique based on the ping-pong effect
Electrochemical detection is ideally suited for miniaturized sensors, as it directly translates chemical information into electrical
signals that can be manipulated on the same chip. Because a typical electrochemical reaction involves the transfer of only
one or a few electrons between a molecule and an electrode, however, detecting a single molecule in this way represents an
enormous challenge (at least at room temperature, where most real-world sensors need to operate!). To solve this problem,
we have developed a new fluidic device, the nanogap. This consists of two electrodes separated by a thin (<100 nm) layer of
liquid, as shown in figure 1(a). Different voltages are applied to the two electrodes such that one electrode donates electrons
to electrochemically active molecules while the other electrode withdraws electrons. Any electrochemically active molecule
trapped between the electrodes thus acts as a ping-pong ball, shuttling electrons from the first to the second electrode and
giving rise to a small (but measurable) current. Because our device is open to an outside reservoir, the number of molecules
in the nanogap fluctuates with time, giving rise to corresponding steps in the current measured at the electrodes (figure 1(b)).
Our goal in the coming years will be to exploit this new capability for fundamental experiments on stochastic detection and as a
platform for more selective electrochemical sensors.
Prof. dr. serge J.G. lemay“The physics of ions in liquid are directly
relevant to a surprisingly wide array of
research areas of current scientific and
societal interest. These include nanoscience
(the ‘natural’ length scale for ions), energy
(fuel cells, supercapacitors), neuroscience
(signal transduction, new experimental
tools), and health and environment
monitoring (new and better sensors)."
NanoIonics
The goals of the group NanoIonics (NI) are to add to fundamental
understanding of electrostatics and electron transfer in liquid,
and to explore new concepts for fluidic devices based on this new
understanding. Our experimental tools, which are largely dictated
by the intrinsic nanometer scale of the systems that we study,
include single-molecule techniques borrowed from biophysics,
sensitive electronics, and lithography-based microfabrication.
Through its focus on nanoscience and its multidisciplinary
nature, this research is a natural fit for MESA+.
HIGHLIGHTED PUBLICATION: M.A.G. Zevenbergen, P.S. Singh, E.D. Goluch, B.L. Wolfrum, S.G. Lemay, Stochastic sensing of single molecules in a nanofluidic electrochemical
device, Nano Letters 11 (2011) 2881-2886.
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Nanofluidics for Lab on a Chip Applications
Prof. dr. Jan Eijkel"The Nanofluidics for Lab on a Chip Applications
group aims to perform innovative fluidic research for
biomedical and energy applications."
Fluid flow on the nanoscale is fundamentally different
from fluid flow on the microscale, since another set of
forces becomes dominant. In the Nanofluidics for Lab on a
Chip Applications group (NLCA) we explore fundamental
phenomena of nanoscale fluidics and apply them to subjects
ranging from green energy generation to single-molecule
research and from innovative separation methods to point of
care diagnostics.
Green energy from flowing water with bubbles
Green energy has become an important topic in scientific research, mainly because society is in dire need for novel environmentally-
friendly energy conversion systems. Lab on a Chip technology provides new opportunities to convert fluidic mechanical energy to
electrical energy.
We use a fluidic approach to convert mechanical to electrical energy. When a microfluidic channel with glass walls is filled with an
aqueous solution, the glass walls become electrically charged due to the dissociation of surface groups. This leads to the formation
of an diffuse cloud of mobile counter-ions in the solution directly adjacent to the wall. When we pump the solution through the
channel, these mobile ions move with the flowing liquid thereby creating an electrical current (the ‘streaming current’, IS in figure
1). By placing electrodes at the two ends of the channel, we can capture this current and when we lead it though an external load
we can harvest electrical energy. This is a straightforward and simple way to convert mechanical energy into electrical energy.
The Achilles heel of the above classical mechanism is, that the current not only flows through the load doing useful work (ILOAD) , but
also, uselessly, back through the channel (IC) because the filling solution is electrically conductive. The conversion efficiency as a
result remains low. We now have mended this Achilles heel by injecting air bubbles into the channel via a fluidic T-split (figure 2).
The air bubbles block the backflow of current and thus increase the current flow through the external load. For the same amount
of input energy we now will harvest more output energy. Figure 3 shows how the conversion efficiency increases with increasing
gas pressure, generating more and more bubbles in the channel. A more than 100-fold increase in efficiency was observed due to
bubble injection.
Though the efficiency improvement is remarkable, the total efficiency is still low (inset figure 3). Our research in this NWO-funded
TOP program is now aiming at employing gas-liquid flow to further increase the conversion efficiency.
HIGHLIGHTED PUBLICATION: Y. Xie, D. Sherwood, L. Shui, A. van den Berg, J.C.T. Eijkel, Strong enhancement of streaming current power by application of two phase Flow,
Lab Chip 11 (2011) 4006.
Figure 2: Injection of gas bubbles into the channel increases the
electrical resistance of the channel. As a result a much larger VS
can be obtained, and hence a higher output power ILOAD*VS. The lamp
burns much more brightly.
Figure 3: The conversion efficiency (relative to the efficiency without
gas bubbles), as a function of the gas pressure. The efficiency can
be increased more than 100-fold using bubble injection. Inset: The
total process efficiency however is still low (inset) and efforts are
focussed on further improvement.
Figure 1: The principle of energy harvesting by the streaming
potential. The useful output power obtained in the lamp equals
ILOAD*VS. Due to the low electrical resistance of the aqueous solution,
VS must be small to prevent all current from leaking back as IC
through the channel. This limits the conversion efficiency and the
lamp burns only weakly.
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Prof. dr. Jennifer l. Herek“Fundamental research in
spectroscopy and imaging
shines light on innovation and
technology.”
Exploiting optical and molecular phase relations to improve imaging
Our research on nonlinear microspectroscopy has led to a revolutionary new approach that provides an intuitive and unified description
of the various signal contributions, allowing for direct extraction of the vibrational response [Figure 1]. Three optical fields create a
pair of interfering Stokes-Raman pathways to the same vibrational state. Frequency modulating one of the fields leads to amplitude
modulations on all of the fields. This vibrational molecular interferometry technique allows imaging at high speed free of nonresonant
background, and is able to distinguish between electronic and vibrational contributions to the total signal.
Identifying complex molecules often entails detection of multiple vibrational resonances, especially in the case of mixtures. Phase
shaping of broadband pump and probe pulses allows for the coherent superposition of several resonances, such that specific molecules
can be detected directly and with high selectivity. We have developed an approach for combining spectral phase shaping and closed-
loop optimization strategies to perform chemically-selective nonlinear microscopy [Figure 2]. To predict the optimal excitation profile
we employ evolutionary algorithms that use the vibrational phase responses of five distinct molecules with overlapping resonances
and investigate the effect of phase instability on the optimization.
Optical Sciences
Optical Sciences (OS) is a dynamic and multidisciplinary research group, whose
infrastructure and expertise ranges from near-field probing of (single) molecules
and materials through nonlinear spectroscopy and imaging to nanostructure
fabrication and ultrafast laser spectroscopy. The integration of phase-shaped
femtosecond laser pulses and adaptive learning algorithms within these themes
is leading to exciting new research at the interface of chemistry, physics and
nanomaterials science. Applications include improving the efficiency of solar-
driven photovoltaic and photo catalytic devices, chemically-selective imaging
in biology and pharmacology, and studying wave propagation and nonlinear
phenomena in nanostructured materials.
HIGHLIGHTED PUBLICATIONS: [1] A.C.W. van Rhijn, A. Jafarpour, M. Jurna, H.L. Offerhaus, J.L. Herek, Coherent control of vibrational transitions: Discriminating
molecules in mixtures, Faraday Discussions 153 (2011) 227-235, [2] E.T. Garbacik, J.P. Korterik, C. Otto, S. Mukamel, J.L. Herek, H.L. Offerhaus, Background-free nonlinear
microspectroscopy with vibrational molecular interferometry, Physical Review Letters 107 (2011) 253902.
Figure 1: Comparing the new vibrational molecular
interferometry (VMI) technique to conventional CARS
imaging shows a marked improvement in signal clarity due to
background suppression.
Figure 2: The coherent control learning loop aims to find optimal
pulse shapes to enhance specific chemical signals in nonlinear
imaging.
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Figure 1: Coffee stain formation (a) and its suppression (b) with
electrowetting (EW). EW excitation during the evaporation is
achieved by applying an AC voltage to interdigitated electrodes
in the substrates (red and blue dashes in the top of (b). Images in
the bottom are for micrometer-sized colloidal particles.
Figure 2: Numerically calculated trajectories of tracer particles
in an oscillating drop water drop in ambient oil with time-
dependent contact angle as in electrowetting experiments. The
spiraled trajectories (left) can be decomposed into a time-
periodic oscillatory motion and a net time averaged flow (right),
which leads to a vortex within the drop. The latter is responsible
for suppressing the coffee stain formation in Fig. 1.
Prof. dr. Frieder Mugele“Nanoscience and -technology are
characterized by large surface-to-volume
ratios. At PCF, we develop strategies to
understand and manipulate complex fluid
flows on the micro- and nanometer scale
using various controls of wetting behavior
and interfacial properties including in
particular electrowetting.”
say goodbye to coffee stains: how electrowetting-driven microfluidics controls pattern formation in evaporating colloidal suspensions
Drying drops of complex fluids such as coffee, paint, and blood typically leave behind ring-shaped solid residues on solid surfaces
commonly known as coffee stains. This ubiquitous phenomenon is caused by an evaporation-driven flow from the center of the drop
towards the edge that carries along the solute. The resulting heterogeneous deposition of material is undesired in various coating
processes involving drop deposition, such as including inkjet printing of complex fluids, micro-array technology, and MALDI sample
preparation. We show that electrowetting can be used to generate flows inside evaporating drops that compensate the evaporation-
drive flux and prevent solute accumulation at the drop edge. Rather than being distributed in a wide ring, the entire solute remains
concentrated in a single spot (see figures). This complex microfluidic effect allows to improve the signal-to-noise ratio of MALDI mass
spectrometry by more than an order of magnitude.
Physics of Complex Fluids
The goal of the Physics of Complex Fluids (PCF) group is to understand and
control the physical properties of liquids and solid-liquid interfaces from
molecular scales up to the micrometer meter range. We are particularly
interested in i) nanofluidics, ii) (electro)wetting & microfluidics, iii) soft matter
mechanics. Our research connects fundamental physical and physico-
chemical phenomena in nanotribology and -lubrication, microfluidic two-
phase flow, static and dynamic wetting, superhydrophobicity, drop impact,
drop evaporation to practically relevant applications such as enhanced oil
recovery, inkjet printing, immersion lithography, lab-on-a-chip systems, and
optofluidics.
HIGHLIGHTED PUBLICATIONS: [1] H.B. Eral, D. Mampallil, M.H.G. Duits, F. Mugele, Suppressing the coffee stain effect: how to control colloidal self-assembly in evaporating
drops using electrowetting, Soft Matter 7 (2011) 4954. [2] J.M. Oh, D. Legendre, F. Mugele, Shaken not stirred - on internal flow patterns in oscillating sessile drops,
EuroPhys. Lett. 98 (2012) 34003.
a) without EW b) with EW
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Prof. dr. Guido Mul“We strive to be a major player in
the solar to fuel research arena,
making use of the expertise
and outstanding facilities of the
MESA+ institute to construct
nanostructured materials and
devices.”
Revealing the operation mechanism of a solar to fuel catalyst
Photocatalytic conversion of CO2 and H2O to fuel-like molecules is an ideal reaction to store solar energy in the form of chemical energy
and to close the carbon cycle (the solar to fuel process). One of the most efficient inorganic photocatalysts for this process is based
on a silica matrix functionalized with isolated Titania sites, known as Ti-SBA-15 (SBA-15 is a silica matrix with regular channels). Little
is known about the nature of the intermediates involved in the reaction, and the ways these are formed and decomposed to the final
products. We have performed a systematic study of the light induced reaction of potential intermediates (H2, CO, CH2O (formaldehyde))
over the Ti-SBA-15 catalyst, using an advanced set-up for photocatalysis evaluation (Figure 1). Based on the results, we believe in a
mechanism for CO2 reduction in which CO and formaldehyde are important intermediates, and in which transient Ti–OOH species are
likely involved (Figure 2). We currently explore mild steam treatment of the catalyst, to create a higher effective quantity of accessible
sites. Surface modification of SBA-15 with Lewis bases (primary, secondary, and tertiary amines) to enhance CO2 adsorption is another
direction we pursue. This increases the probability of electron transfer from the photo-excited sites to CO2, which is most likely the
rate limiting step.
Photocatalytic Synthesis
Photocatalysis is based on the use of light activated catalysts in chemical conversion.
Practical application is limited because of problems in light management, such as mismatch
in catalyst sensitivity and solar spectrum, the limited ability of photo-excited states to induce
electron transfer reactions, and lack of efficient light exposure of catalysts in reactors. The
Photocatalytic Synthesis (PCS) group aims at understanding the role of both the physical and
chemical properties of innovative materials in establishing photocatalytic transformations,
to allow improved catalyst design. We also study the effect of process conditions and reactor
geometry on performance, to establish operation of devices with high efficiency. Fields of
application we target are: 1) conversion of CO2 and H2O to hydrocarbons, 2) alkane activation,
and 3) purification of waste streams (air and water).
HIGHLIGHTED PUBLICATION: C. Yang, J. Vernimmen, V. Meynen, P. Cool, G. Mul, Journal of Catalysis 284 (2011) 1-8
Figure 2: Illustration of the global description of the mechanism
of solar to fuel synthesis over catalytic Ti-centers (Ti-OH)
embedded in a silica matrix, yielding methane, ethane, and
ethylene by conversion of CO2 and H2O.
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Figure 1: Overview of the multiple batch reactor used to
study solar to fuel chemistry of up to 12 photo-catalysts
simultaneously. Analysis of the gas phase products is performed
by micro-Gas Chromatography.
Ultrafast decay of Pb-islands on Ni(111)
The morphology of thin films is subject to a sometimes complex interplay between kinetics and thermodynamics of the film-substrate.
A nice, unanticipated example of the possible intricacy of processes underlying the evolving morphology was observed during the
growth of Pb/Ni(111) at 474 K: 38 monolayers high Pb-mesas develop, which only cover 31% of the substrate. These flat-topped islands
are stabilized by quantum well states in the Pb-film, i.e. standing waves with the lead Fermi wavelength. Slow heating makes the Pb-
mesas collapse into hemispheres at ~525 K, i.e. well below the melting temperature. Figure 1 illustrates this process. The collapse is
incredibly fast: a billion Pb-atoms move within 2 milliseconds over hundreds of nanometers! This spectacular diffusivity outnumbers
the values for atomic events, as obtained from SPM and first principle calculations, by six orders of magnitude! Improved knowledge
of physics at the mesoscopic length scale must be developed to understand the process.
Knudsen gas provides nanobubble stability
Surface nanobubbles are a recent discoveries in interfacial physics. They are nanoscopic gaseous domains that form at the solid/liquid
interface. The fundamental interest focuses on the fact that they are surprisingly stable to dissolution, lasting for at least 10 orders
of magnitude longer than the classical expectation. We provide a model for the remarkable stability of surface nanobubbles to bulk
dissolution. The key to the solution is that the gas in a nanobubble is of Knudsen type. This leads to the generation of a bulk liquid
flow which effectively forces the diffusive gas to remain local. Our model predicts the presence of a vertical water jet immediately
above a nanobubble, with an estimated speed of a few m/s in good agreement with our atomic force microscopy measurements.
HIGHLIGHTED PUBLICATIONS: T.R.J. Bollmann, R. van Gastel, H.J.W. Zandvliet, B. Poelsema, Anomalous decay of electronically stabilized lead mesas on Ni(111), Physical Review Letters
107(13) (2011) 136103. [2]. T.R.J. Bollmann, R. van Gastel, H.J.W. Zandvliet, B. Poelsema, Quantum size effect driven structure modifications of Bi films on Ni(111), Physical Review Letters
107(17) (2011) 176102. [3]. J.R.T. Seddon, H.J.W. Zandvliet, D. Lohse, Knudsen gas provides nanobubble stability, Physical Review Letters 107(11) (2011) 116101. [4] J.R.T. Seddon, E.S. Kooij, B.
Poelsema, H.J.W. Zandvliet, D. Lohse, Surface bubble nucleation stability, Physical Review Letters 106(5) (2011) 056101.
Prof. dr. ir. Harold J.W. Zandvliet“Emerging nanoscopic techniques, such
as low energy electron microscopy and
He ion microscopy, have provided us
with new insights that went far beyond
our wildest expectations.”
Physics of Interfaces and Nanomaterials
The research field of the Physics of Interfaces and Nanomaterials (PIN)
group involves controlled preparation and understanding of interfaces,
low-dimensional (nano)structures and nanomaterials. We focus on systems
that (1) rely on state-of-the art applications or (2) can potentially lead to
future applications. Our research interest is driven by the fact that on a
nanometer length scale the material properties depend on size, shape and
dimensionality. A key challenge of our research activities is to obtain control
over the properties in such a way that we are able to tailor the properties for
(device) applications, ranging from nano/micro-electronics, nano-electro-
mechanical systems and wettability to sustainable energy related issues.
Figure 2: Knudsen gas streaming and nanobubble geometry. (a)
The broken symmetry created between one solid surface and
one ‘leaky’ liquid/gas interface leads to bulk upwards flow in the
Knudsen gas. (b) The tangential component of the bulk Knudsen
gas flow drives a bulk liquid flow due to the continuity of shear
stress at the liquid/gas interface. (c) Finally, due to conservation
of mass, this gas-rich liquid stream circulates upwards at the
bubble apex and back around to the three-phase line, effectively
transporting the diffusive outfluxing gas back to the three-phase
line for re-entry.
Figure 1: (a) Sum of two consecutive LEEM frames with
acquisition time 80 ms. The light grey area refers to the mesa
which has collapsed into a hemisphere (dark area) in the second
frame. (b) Cartoon of the process.
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Prof. dr. ir. Hajo Broersma"Evolution has a huge impact
on living organisms and their
successful survival. Now is the time
to apply fast computer-controlled
evolution to dead matter in order to
produce energy-efficient and useful
components for our future survival."
NASCENCE: Nanoscale Engineering for Novel Computation using Evolution
NASCENCE is a FET research project within the framework of the Call FP7-ICT-2011.9.6 Unconventional Computation (UCOMP).
The aim of this project is to model, understand and exploit the behaviour of evolving nanosystems (e.g. networks of nanoparticles,
carbon nanotubes or films of graphene) with the long term goal to build information processing devices exploiting these architectures
without reproducing individual components. With an interface to a conventional digital computer we will use computer controlled
manipulation of physical systems to evolve them towards doing useful computation.
During the project our target is to lay the technological and theoretical foundations for this new kind of information processing
technology, inspired by the success of natural evolution and the advancement of nanotechnology, and the expectation that we soon
reach the limits of miniaturisation in digital circuitry (Moore's Law). The mathematical modelling of the configuration of networks
of nanoscale particles combined with the embodied realisation of such systems through computer controlled stochastic search
can strengthen the theoretical foundations of the field while keeping a strong focus on their potential application in future devices.
Members of the consortium have already demonstrated proof of principle by the evolution of liquid crystal computational processors
for simple tasks, but these earlier studies have only scraped the surface of what such systems may be capable of achieving.
With this project we want to develop alternative approaches for situations or problems that are challenging or impossible to solve with
conventional methods and models of computation. Achieving our objectives fully would provide not only a major disruptive technology
for the electronics industry but probably the foundations of the next industrial revolution.
Overall, we consider that this is to be a highly adventurous, high risk project with an enormous potential impact on society and
the quality of life in general. Apart from the Programmable NanoSystems group, other UT groups involved are NanoElectronics,
Mathematics of Computational Science, Formal Methods and Tools, and Computer Architectures for Embedded Systems. The other EU
consortium partners involved in the NASCENCE project are located in Durham, Lugano, Trondheim and York.
Programmable nanoSystems
Men has been able to design, build and integrate electronic circuits very
successfully, but it is a huge challenge to build complex, fault tolerant
systems for more complicated functionality. Interestingly, nature itself has
managed to do this through a relatively simple process of evolutionary
testing and modifying, and it succeeded to do so in a universe of great
physical complexity. Within the Programmable NanoSystems (PNS) group
we explore the theoretical and experimental possibilities of using systems of
nanomaterials as a black box for computational tasks by developing genetic
and evolutionary algorithms to control and modify the external impulses that
will be used to (re)configure the computational properties of the material.
Figure 1: a schematic illustration of the set-up.
Figure 2 (a): a prototype interface.
Figure 2 (b): the material disc with a micro-electrode-array.
Figure 2 (c): a film of nanotubes on the array.
Order-to-disorder transition in a coffee stain
When a droplet containing suspended particles, such as coffee, evaporates, a ring-shaped stain is left behind on the substrate; see Fig.
1. This coffee-stain effect was first explained by Robert Deegan et al. [1]: in an evaporating drop with a pinned contact line, a capillary
flow is generated to replenish the liquid that has evaporated from the drop edge. This flow drags along the particles, which are then
deposited at the contact line. We have studied the dynamics of the ring stain formation in water drops with polystyrene particles [2]. As
shown in Fig. 2, the remaining stains showed a remarkable structure: in the outermost layers of the stain, the particles have aggregated
in a crystalline way, whereas further inwards the particle packing becomes very disordered.
To explain this peculiar particle ordering, it is crucial to understand the dynamics of the droplet evaporation. To this end, we filmed the
droplets simultaneously from the sides and from below, and performed micro-PIV to measure the velocity field inside the droplets. A rush-
hour of particles was observed during the last moments of the droplet’s life: the particle velocity increases dramatically as the droplet
height decreases to zero. This temporal divergence of the velocity can be understood quantitatively from simple mass conservation. This
is induces a diverging radial velocity at the of the droplet life.
The order-to-disorder transition in the remaining stain can be explained by this rush-hour behavior in the particle velocity. Particles that
arrive early, when the deposition rate is still low, have time to arrange by Brownian motion and form an ordered structure. Particles that
arrive during the rush hour have no time for such arrangement and form a jammed, disordered pattern. We can predict when the order-
to-disorder transition will occur by comparing the particle diffusion time to the typical arrival time. A critical particle speed is obtained
when these two timescales are equal: particles that arrive at a lower speed will form the ordered phase, particles with a higher speed
the disordered phase.
HIGHLIGHTED PUBLICATIONS: [1] A.G. Marin, H. Gelderblom, D. Lohse, J.H. Snoeijer, Order-to-Disorder Transition in Ring-Shaped Colloidal Stains, PRL 107 (2011) 085502. [2]
D.P.M. van Gils, S.G. Huisman, G.W.H. Bruggert, C. Sun, D. Lohse, Torque Scaling in Turbulent Taylor-Couette Flow with Co- and Counterrotating Cylinders, PRL 106 (2011)
024502. See also: Pysics Today, January 2011. [3] J.R.T. Seddon, H.J.W. Zandvliet, D. Lohse, Knudsen Gas Provides Nanobubble Stability, PRL 107 (2011) 116101. [4] J.R.T. Seddon,
E.S. Kooij, B. Poelsema, H.J.W. Zandvliet, D. Lohse, Surface Bubble Nucleation Stability, PRL 106 (2011) 056101.
Prof. dr. Detlef lohse“The physics of fluids
is very different on the
nano- and micro-scale
as compared to the
macro-scale and offers
various challenges of both
fundamental and applied
character.”
Physics of Fluids
The Physics of Fluids (PoF) group is studying
various flow phenomenona, both on a micro-
and macro-scale. We use both experimental,
theoretical, and numerical techniques and we
do both fundamental and applied research. Our
main research areas are:
n Turbulence and Two-Phase Flow
n Granular Flow
n Biomedical Application of Bubbles
n Micro- and Nanofluidics
Figure 1: Coffee stains with their characteristic dark rings on a
desk.
Figure 2: a) A water droplet containing 1-micrometer polystyrene
particles on a glass slide. b) The ring-shaped stain of particles
left on the substrate after the droplet has evaporated. c) The
same stain 50x enlarged. Particles in the outermost layers have
arranged in a crystalline way, whereas the inner layers have a
disordered structure. d) The stain 2x further enlarged, to show the
crystalline structure of the particles.
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smoluchowski-Feynman ratchet in a granular gas
Molecular motors, such as those responsible for tensing and relaxing your muscles, move in a strange manner: They propel
themselves forwards despite - or thanks to - a continuous bombardment of the randomly moving molecules in their surroundings.
This random movement is called Brownian motion and a well-constructed motor at the nanoscale actually makes use of this to
generate a directed movement (and therefore work).
In 1912 the physicist Marian Smoluchowski - as a gedankenexperiment - introduced a clever device that is a classical example
of such a motor. It consists of a series of vanes mounted on an axis, which are set in motion under the influence of the molecular
bombardment. As this motion would take place in both rotational directions, Smoluchowski devised a second element, a ratchet
and pawl. This would ensure that the axis could only rotate in a single direction and could therefore perform work, for example by
pulling a small weight up. However, in 1963 Richard Feynman demonstrated that the second law of thermodynamics would prevent
the device from working in a system that was in a state of thermal equilibrium. With this, the gedankenexperiment appeared to
have been consigned to the waste bin.
Yet the objection formulated by Feynman does not apply to a system that is far from thermal equilibrium, such as a granular
gas that is created by vigorously vibrating a container filled with beads on top of a shaking device. Using both experiments
and numerical simulations we have successfully demonstrated that Smoluchowski’s device works superbly in this environment.
In addition we found an unpredicted feature: the interplay of the moving vanes and the granular gas spontaneously creates a
convection roll within the system. This roll breaks the symmetry on its own accord, without the need of introducing a ratchet and
a pawl to force the broken symmetry.
Dr. Devaraj van der Meer"What fascinates me in granular matter
is that in many aspects it resembles an
ordinary molecular fluid or solid. And at
the same time it adds a complete new
dimension of unexpected or even mind-
boggling phenomena."
Physics of Granular Matter and Interstitial Fluids
Granular materials, like sand, flour or iron ore, are among the most frequent
materials in nature and are the most processed substance in industry, second
only to water. Their often counterintuitive behavior however is distinctly
different from that of molecular matter and remains far from understood. The
Physics of Granular Matter and Interstitial Fluids (PGMF) group employs a
combination of experiments, analysis and numerical techniques to attain to
a profound understanding of the physics of granular flow. Special attention is
given to unraveling the intricate role of the interstitial fluid, the gas or liquid
that resides within the pores between the grains. The group is embedded into
the Physics of Fluids group.
HIGHLIGHTED PUBLICATIONS: [1] S. Joubaud, D. Lohse, D. van der Meer, Fluctuation theorems for an asymmetric rotor in a granular gas, Phys. Rev. Lett. 108 (2012)
210604. [2] P. Eshuis, K. van der Weele, D. Lohse, D. van der Meer, Experimental realization of a rotational ratchet in a granular gas, Phys. Rev. Lett. 104 (2010) 248001.
Figure 2: Smoluchowski's device is brought to life in a granular
gas: a top view of the experimental device in operation (left) and a
side view of the simulation (right).
Figure 1: Smoluchowski’s gedankenexperiment with the vanes
on the right, the ratchet and pawl on the left and in the middle a
pulley with a weight.
(62)HIGHLIGHTED PUBLICATION: M. Veldhorst, M. Snelder, M. Hoek, T. Gang, V. Guduru, X. Wang, U. Zeitler, W.G. van der Wiel, H. Hilgenkamp, A. Brinkman, Josephson
supercurrent through a topological insulator surface state, Nature Materials 11 (2012) 417. [arxiv preprint cond-mat\1112.3527 (2011).]
Quantum Transport in Matter
Prof. dr. ir. Alexander Brinkman"It is fascinating to exploit quantum
effects such as entanglement
and non-locality in materials and
electronic devices."
Superconducting topological nanostructure first step towards Majorana fermion
Topological insulators and superconductors are two very special electronic materials. Topological insulators are electrical insulators
in the bulk but conduct at the surface. The surface conduction has the special property that the spin of the electrons is coupled to
the direction in which they move. A superconductor conducts electricity without resistance.
MESA+ researchers have now realized a sandwich nanostructure of a Bi2Te3 topological insulator in between two Nb superconductors
(see Figure 1). By combining measurements at large magnetic fields at the HFML in Nijmegen with electrical measurements at low
temperatures it could be shown that the surface of Bi2Te3 indeed behaves topologically. By measuring so called Josephson effects (see
Figure 2) they have shown that a supercurrent can flow from one superconductor to the other through a topological insulator surface
state over a distance of the order of 100 nm.
In 1937 the Italian physicist Ettore Majorana predicted the existence of fermionic particles that could be their own anti-particle.
Theory predicts that a superconducting topological insulator might host these particles. The realized nanostructures therefore now
form an important technological platform to investigate the presence and properties of these particles. Majorana fermions bear the
potential of reducing the problem of decoherence of quantum states and these particles could experimentally open up the new field
of topological quantum computation.
The Quantum Transport in Matter (QTM) group is
founded in 2011 by the appointment of its chair
prof. dr. ir. Alexander Brinkman. It is the aim of the
group to explore the electronic transport effects of
quantum phenomena in materials and electronic
devices. The research in the group builds on recent
nanotechnological and thin film technological
developments within MESA+ and with advanced
electronic transport experiments a quantum
mechanical dimension is given to the research.
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Figure 1: Top: Atomic force micoscopy image of the smooth
surface of the topological insulator bismuth-telluride (Bi2Te3).
Bottom: Electron microscopy image of the superconductor
– topological insulator nano sandwich. The spacing between
the Nb superconducting electrodes on top of the Bi2Te3 flake
increases (from left to right: 50, 100, 150, 200, 250 and 300
nanometer).
Figure 2: The color-coded resistance is measured as function
of current (horizontal axis) and microwave irradiation power
(vertical axis). This 'Bessel-peacock' image results from the ac
Josephson effect.
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Measurement of the temperature of a substrate surface
In many new processes, employed in integrated circuit manufacturing and solar cell production, a condition is created where
temperature equilibrium is disturbed on purpose. Examples include plasma processing, laser treatments and rapid thermal
anneals. It is often difficult to determine the temperature at the surface of the substrate under treatment; while the surface
temperature is a critical parameter for the result of this treatment.
A kind of temperature dosimeter was developed by postdoc Erik Faber to solve this problem. The dosimeter has a resistance that
will change permanently and in a predictable manner when it is heated up. A resistive structure is made on top of the substrate,
that consists of two films, typically silicon and a transition metal. Upon heating, a diffusion-limited chemical reaction takes place
leading to the thinning of the original films and the formation of a new alloy. The resistance change is a direct measure of the
amount of diffusion that has taken place.
The effect of resistance change is strongly enhanced by forming structures with a submicrometer gap (as shown in figure 1). The
gap closes upon high-temperature annealing by the same process as described above. Figure 2 exemplifies how the resistance
evolves over time in this gap-type resistive structure.
The approach has been patented in 2010 and led to several journal and conference publications. This research was sponsored by
the Dutch Technology Foundation STW.
Prof. dr. Jurriaan Schmitz"Microchips are great, but we want
them better still. In the EE-group
Semiconductor Components we study
new materials and new device concepts
for integrated circuits."
Semiconductor Components
The research program of Semiconductor Components (SC) deals with silicon-
based technology and integrated-circuit devices. Scope of the group is “More
than Moore” microtechnology. Our aim is to contribute to this emerging field
by developing low-temperature processing techniques, adding functionality
to completed CMOS microchips, and developing novel devices. The research
comprises thin film deposition; the integration of new components (such as silicon
LED’s and elementary particle detectors) into CMOS; and advanced device physics
and modelling. The group has strong ties with Philips, NXP Semiconductors, ASM
International, and the CTIT-group IC-design. The Dutch Technology Foundation
STW and the Ministry of Economic Affairs are the main funding sources.
HIGHLIGHTED PUBLICATIONS: [1] E. Faber, R.A.M. Wolters, J. Schmitz, On the kinetics of platinum silicide formation, Applied Physics Letters 98(8) (2011) 082102.
[2] E. Faber, R.A.M. Wolters, J. Schmitz, Novel test structures for dedicated temperature budget determination, IEEE Transactions on Semiconductor Manufacturing, in
press (2012).
Figure 2: Typical resistance evolution over time during
annealing at 350 °C. The higher two curves show experiments
where the layer thicknesses in the bilayer were incorrectly
chosen for the effect to occur. The bottom curves show distinct
changes in resistance, each representing the closure of one of
the gaps. The resistance change observed in this experiment
is permanent, allowing for measurements after the high-
temperature step in a dedicated probe station.
Figure 1: Top view of a metal pattern on a thin layer of silicon.
The resistance from bottom to top will decrease when the gaps
close during a high-temperature treatment.
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HIGHLIGHTED PUBLICATIONS: [1] H.C. Aran, S. Pacheco Benito, M.W.J. Luiten-Olieman, S. Er, M. Wessling, L. Lefferts, N.E. Benes, R.G.H. Lammertink, Carbon nanofibers
in catalytic membrane microreactors, Journal Of Membrane Science, 381(1-2) (2011) 244-250. doi:10.1016/j.memsci.2011.07.037. [2] H.C. Aran, D. Salamon, T. Rijnaarts, G.
Mul, M. Wessling, R.G.H. Lammertink, Porous Photocatalytic Membrane Microreactor (P2M2): A new reactor concept for photochemistry, Journal Of Photochemistry And
Photobiology A-Chemistry (2011) doi:10.1016/j.jphotochem.2011.09.022.
Prof. dr. ir. Rob G.H. Lammertink“Understanding and
optimizing processes at
the interface.”
Advanced microreactors for clean water
Microreactors have very large surface to volume ratios, enabling the development of more efficient processes. We develop advanced
microreactors with integrated membrane technology for multiphase processes (Gas-Liquid-Solid systems). These reactors were
utilized for catalytic reduction and photocatalytic oxidation reactions in water, which are of great importance for water treatment. In
collaboration with the PCS, CPM and IM groups, we fabricated, analyzed, and characterized hybrid microreactors. Porous stainless
steel hollow fibers were covered with carbon nanofibers with high surface area as catalyst support. Subsequently, a palladium catalyst
was deposited for catalytic hydrogenation of nitrite ions in water. These reactors showed superior reduction properties of nitrite ions,
even in the absence of palladium catalyst and hydrogen gas, thanks to the reductive properties of the reactor material itself.
For oxidative processes, the Porous Photocatalytic Membrane Microreactors (P2M2) concept benefits from a stable gas-liquid-solid
interface by the use of a porous membrane and a reduced light path for multiphase photocatalytic reactions. This reactor has tailored
surface properties with a hydrophobic porous membrane support and a hydrophilic photocatalytic microchannel. We applied these
reactors for photocatalytic degradation processes. Additional membrane-assisted oxygen supply increased the reactor performance
drastically, even at dilute concentration of oxygen.
The Soft matter, Fluidics and Interfaces (SFI) group is addressing
interfacial phenomena that are relevant for transport processes.
Careful interfacial design and fabrication will allow manipulating
(multiphase) flow on a (sub)micrometer level. Fabrication of
well-defined structures is a crucial aspect, in order to study the
fundamentals of interfacial phenomena. The connection between
microfluidics and interfaces is evident as interfacial phenomena start
to dominate at small length scales. A fundamental understanding
at the microscopic length scale is required to understand and
manipulate transport phenomena.
Soft matter, Fluidics and interfaces
Figure 1: Porous stainless steel hollow fiber decorated with
carbon nanofibers (CNFs) and deposited palladium catalyst.
Figure 2: P2M2 (porous photocatalytic membrane
microreactors) during operation under UV-Light.
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Science, Technology and Policy Studies
HIGHLIGHTED PUBLICATIONS: [1] H. te Kulve, A. Rip, Constructing Productive Engagement: Pre-engagement Tools for Emerging Technologies, Sci Eng Ethics (2011)
17:699-714. [2] M. Ruivenkamp, Circulating Images of Nanotechnology (21 April 2011). [3] H. te Kulve, Anticipatory Interventions in the Co-evolution of Nanotechnology
and Society (21 April 2011). [4] C. Shelley-Egan, Ethics in Practice: Responding to an Evolving Problematic Situation of Nanotechnology in Society (13 May 2011).
The department Science, Technology and Policy Studies (ST PS) investigates the dynamics
and governance of science, technology and innovation from an interdisciplinary social science
perspective. Our research covers ongoing dynamics, historical developments and future-oriented
studies. Studying such dynamics is a goal in itself, but also an important prerequisite for policy
recommendations and exploring strategic implications for innovation actors. In the area of
nanotechnologies, studies (funded by NanoNed, NanoNextNL, European Union) have focused on
Constructive Technology Assessment in various domains as lab on a chip, deep brain implants,
food packaging, and drug delivery. We also study organizational and institutional issues like
collaboration in science, practices of responsible innovation, promises and concerns, and sectoral
implications. In 2011, three PhD theses on issues of nanotechnology and society were completed
under supervision of Arie Rip. A number of new PhD and postdoc projects have started, supervised
by Kornelia Konrad and Stefan Kuhlmann.
Prof. dr. arie rip“Bridge the gap between innovation
and ELSA (Ethical, Legal and Social
Aspects).That’s our aim, so we focus
on what happens in and around the
nano-world, rather than on public
responses to nanotechnology.
And we work towards improving
the anticipation on embedding of
nanotechnology in society."
nano in food packaging: current dynamics and future scenarios
The extent to which, and how, nanotechnologies are taken up in an application domain, here food and food packaging, depends on
the specific conditions within the industry (including customers and end consumers) and the more or less successful coordination
of activities of relevant actors within the sector. Anticipation, particularly with the help of scenarios, is important for a critical
assessment of the potential and impacts of nanotechnologies, and for supporting stakeholders in developing appropriate strategies.
Such scenarios will also include presently less visible actors which may become important in the near future. The article argues
that engagement of business and other actors in such anticipatory activities is important, and that this needs proper preparation
and timing to be effective. Scenarios are used in strategy-articulation workshops. To draw up such scenarios requires analysis of
ongoing societal and technological developments, drawing on an understanding of general patterns in innovation processes so as
to map dynamics and do “controlled speculation” about possible futures.
The current situation in the food packaging sector is one of cautious uptake of nanotechnology because of concerns over possible
concerns of consumers. Also, business actors are waiting for others to make the first move. Attempts to break through this “waiting
game” will have different repercussions. The scenarios trace possible outcomes of such attempts. One possibility is a shift away
of research from long-term advanced packaging solutions to more short-term applications, eventually resulting in a decrease
of interest in nano for food packaging. A second scenario shows how proactive regulation may support trust, but also create a
competitive advantage for big firms compared to smaller companies. In a third scenario researchers and industrialists create
nano-platforms, which expand into a broader forum linking also critical NGOs and pharmaceutical companies, thus creating trust
and momentum for further developments.
Actors involved in food packaging – schematic presentation and
interacting at a scenario workshop.
Figure 1: (left) Planar Pt electrodes after the alternating pulse
process . Visible destruction of electrodes due to reaction in
the bubbles is in good correspondence with the current density.
(right) AFM image of the destructed area on the electrode.
Significant displacement of the material is visible.
Figure 2. Schematic explanation of the process. (left) Voltage
pulses of alternating polarity produce bubbles containing
mixture of both gases. (middle) If the pulses are short, the
bubbles will be small enough to explode. Optical images of
gold electrodes before and after the process are presented.
(right) The graph shows the current in the system (red) and the
vibrometer signal (blue). The signal peaks correlating with the
current demonstrate periodic decrease in gas amount in the
liquid due to the reaction.
Prof. dr. ir. Gijs Krijnen “The fabrication of complex 3D
micro- and nano-objects is going to
be a main challenge for the near
future. A combination of photo-
lithography based technologies with
self-assembly is one potential solution
to this challenge.”
Combustion of oxygen-hydrogen mixture in nanobubbles
How small can the combustion chamber of an engine be? It is largely believed that it cannot be very small, and has to be larger
than, say, 100 micrometers, or so. This is because the heat needed to sustain a fast chemical reaction escapes via the chamber walls
more efficiently for small chambers, and temperatures required for combustion cannot be reached. Our research showed that this
truth is not universal and combustion can proceed in chambers as small as 100 nanometers or even less. Using electrolysis of water
we produced small bubbles containing a mixture of oxygen and hydrogen. This is possible when short voltage pulses of alternating
polarity are applied to the electrodes, producing each gas periodically in the same location. The faster the polarity switches, the smaller
formed bubbles are. We discovered that for a switching time smaller than 25 microseconds the reaction in the bubbles is ignited
spontaneously. This switching time results in the formation of bubbles smaller than 150 nanometer in diameter, which subsequently
explode.
A sudden disappearance of visible gas production was observed for switching frequencies higher than 20 kHz, while for single
polarity pulses the visible gas was produced in accordance with expectations. The disappearance of gas was accompanied by a
considerable destruction of platinum electrodes, as shown in Figure 1 (left). Atomic force microscope image shows that this is due
to material displacement (Figure 1, right). The destruction was weaker for a tough material such as tungsten and stronger for a soft
material such as gold. Interferometric measurements showed that the gas concentration in liquid is reduced periodically in correlation
with the voltage pulses (Figure 2, right). With the help of an external probe positioned nearby the electrodes the thermal effect of the
reaction was measured. The precise mechanism of the reaction in the nanobubbles is not clear yet, but it is likely that fast microseconds
dynamics and high Laplace pressure in nanobubbles are involved.
transducer Science and technology
At Transducer Science and Technology (TST) we specialize in 3D
nano- and micro fabrication, combining top down lithography
based methods with directed- and self-assembly. We invent new
fabrication techniques and acquire fundamental understanding on
the underlying physics. We demonstrate the techniques on various
devices and develop the science of working principles and design,
with the aim to ultimately transfer this knowledge to industry. We
work on three generations of fabrication technologies -MEMS,
nanotechnology and self-assembly- thus covering the range
between fundamental research and application.
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HIGHLIGHTED PUBLICATIONS: [1] V.B. Svetovoy, R.G.P. Sanders, T.S.J. Lammerink, M.C. Elwenspoek, Combustion of hydrogen-oxygen mixture in electrochemically
generated nanobubbles, Physical Review E 84 (2011) 035302(R). [2] L.A. Woldering, L. Abelmann, M.C. Elwenspoek, Predicted photonic band gaps in diamond-lattice
crystals built from silicon truncated tetrahedrons, J. Appl. Phys. 110 (2011) 043107; http://dx.doi.org/10.1063/1.3624604. [3] W.W. Koelmans, A. Sebastian, L. Abelmann, M.
Despont, H. Pozidis, Force modulation for enhanced nanoscale electrical sensing, Nanotechnology 22 (25) (2011) 1-9.
Mesa+ annual rePort 2011
PHD tHeses
Abdulla, S.M.C. (2011, April 06). Integration of Micro-cantilevers with Photonic Structures
for Mechano-optical Wavelength Selective Devices. University of Twente (170 pag.). Prom./
coprom.: Dr.ir. G.J.M. Krijnen.
Andreski, A. (2011, September 15). Superconducting Circuits with Pi-shift Elements. University
of Twente (344 pag.). Prom./coprom.: Prof.dr.ir. J.W.M. Hilgenkamp.
Andricciola, P. (2011, December 21). Interpretation of MOS transistor mismatch signature
through statistical device simulations. University of Twente (149 pag.). Prom./coprom.: Prof.
dr. J. Schmitz & H.P. Tuinhout.
Al-Hadidi, A.M.M. (2011, February 25). Limitations, improvements, alternatives for the silt
density index. University of Twente (196 pag.). Prom./coprom.: Prof.dr.ir. W.G.J. van der Meer
& Dr.ir. A.J.B. Kemperman.
Aran, H.C. (2011, November 04). Porous ceramic and metallic microreactors - tuning interfaces
for multiphase processes. University of Twente (126 pag.). Prom./coprom.: Prof.dr.ir. R.G.H.
Lammertink & Prof.dr.-ing. M. Wessling.
Bakker, G.J. (2011, July 08). LFA-1 dynamics on the membrane of leukocytes: a single dye
tracing study. University of Twente (148 pag.). Prom./coprom.: Dr. M.F. Garcia Parajo & Prof.
dr. N.F. van Hulst.
Beer, S.J.A. de (2011, May 27). Probing the properties of confined liquids. University of Twente
(187 pag.). Prom./coprom.: Prof.dr. F. Mugele & Dr. H.T.M. van den Ende.
Bettahalli Narasimha, M.S. (2011, February 04). Membrane supported scaffold architectures
for tissue engineering. University of Twente (180 pag.). Prom./coprom.: Prof.dr.-ing. M.
Wessling & Dr. D. Stamatialis.
Bliznyuk, O. (2011, July 07). Directional wetting on patterned surfaces. University of Twente
(129 pag.). Prom./coprom.: Prof.dr.ir. B. Poelsema.
Bollmann, T.R.J. (2011, September 23). Escape from Flatland: strain and quantum size effect
driven growth of metallic nanostructures. University of Twente (108 pag.). Prom./coprom.:
Prof.dr.ir. B. Poelsema & J.W.M. Frenken.
Boogaard, A. (2011, January 12). Plasma-enhanced chemical vapor deposition of silicon
dioxide : optimizing dielectric films through plasma characterization. University of Twente
(186 pag.). Prom./coprom.: Prof.dr.ir. R.A.M. Wolters & A.Y. Kovalgin.
Boogaard, A.J.R. van den (2011, December 13). Ion-enhanced growth in planar and structured
Mo/Si multilayers. University of Twente (104 pag.). Prom./coprom.: Prof.dr. F. Bijkerk.
Bos, J.A. van der (2011, January 14). Air Entrapment and Drop Formation in Piezo Inkjet Printing.
University Twente (119 pag.). Prom./coprom.: Prof.dr. D. Lohse & Dr. M. Versluis.
Boschker, J.A. (2011, February 04). Perovskite oxide heteroepitaxy; strain and interface
engineering. University of Twente (142 pag.). Prom./coprom.: Prof.dr.ing. D.H.A. Blank & Prof.
dr.ing. A.J.H.M. Rijnders.
Bruijn, S. (2011, April 27). Diffusion phenoma in chemically stabilized multilayer structures.
University of Twente (114 pag.). Prom./coprom.: Prof.dr. F. Bijkerk.
Chen, J. (2011, July 01). Characterization of EUV induced contamination on multilayer optics.
University of Twente (119 pag.). Prom./coprom.: Prof.dr. F. Bijkerk.
Chen, S. (2011, October 13). Silicon Nanowire Field-effect Chemical Sensor. University of
Twente (126 pag.). Prom./coprom.: Prof.dr.ir. A. van den Berg & E.T. Carlen.
Dagamseh, A.M.K. (2011, December 21). Bio-inspired Hair Flow Sensor Arrays: From Nature
to MEMS. University of Twente (173 pag.). Prom./coprom.: Dr.ir. G.J.M. Krijnen & Dr.ir. R.J.
Wiegerink.
Dalwani, M.R. (2011, November 11). Thin film composite nanofiltration membranes for extreme
conditions. University of Twente (160 pag.). Prom./coprom.: Prof.dr.-ing. M. Wessling & Dr.ir.
N.E. Benes.
Domanski, M. (2011, September 02). Nanofabrication methods for improved bone implants.
University of Twente (174 pag.). Prom./coprom.: Prof.dr. J.G.E. Gardeniers & Dr. R. Luttge.
Dutczak, S.M. (2011, November 11). Solvent resistant nanofiltration membranes. University of
Twente (141 pag.). Prom./coprom.: Prof.dr.-ing. M. Wessling & Dr. D. Stamatialis.
Duvigneau, J. (2011, February 11). Scanning Thermal Lithography for Nanopatterning of
Polymers. Transient Heat Transport and Thermal Chemical Functionalization Across the
Length Scales. University of Twente (183 pag.). Prom./coprom.: Prof.dr. G.J. Vancso.
MESA+ Scientific Publications 2011
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[SCiEntiFiC PubliCAtionS]
Embrechts, A. (2011, May 19). Single Molecule Force Spectroscopy of self complementary
hydrogen-bonded supramolecular systems: dimers, polymers and solvent effects. University
of Twente (166 pag.). Prom./coprom.: Prof.dr. G.J. Vancso & Dr. H. Schönherr.
Engelen, J.B.C. (2011, January 14). Optimization of Comb-Drive Actuators [Nanopositioners for
probe-based data storage and musical MEMS]. University of Twente (124 pag.). Prom./coprom.:
Prof.dr. M.C. Elwenspoek & Dr.ir. L. Abelmann.
Eral, H.B. (2011, March 04). Colloidal suspensions under external control. University of Twente
(214 pag.). Prom./coprom.: Prof.dr. F. Mugele & Dr. M.H.G. Duits.
Everts, F. (2011, January 28). Characterization of nanometre-scale patterns on Cu(001) and
Ag(001) by means of optical spectroscopy and high-resolution electron diffraction. University
of Twente (103 pag.). Prom./coprom.: Prof.dr.ir. B. Poelsema.
Gang, T. (2011, October 28). Assemly and Magneto-Electrical Characterization of Hybrid
Organic-Inorganic Systems. University of Twente (142 pag.). Prom./coprom.: Prof.dr.ir. W.G.
van der Wiel & Prof.dr.ing. D.H.A. Blank.
Geskus, D. (2011, November 16). Channel waveguide lasers and amplifiers in single-
crystalline ytterbium-doped potassium double tungstates. University of Twente (155 pag.).
Prom./coprom.: Prof.dr. M. Pollnau & Dr. K. Wörhoff.
George, A. (2011, December 15). Sub-50 nm Scale to Micrometer Scale Soft Lithographic
Patterning of Functional Materials. University of Twente (86 pag.). Prom./coprom.: Dr.ir. J.E. ten
Elshof & Prof.dr.ing. D.H.A. Blank.
Gomez Casado, A. (2011, July 15). Strength and dynamics of multivalent complexes at surfaces.
University of Twente (157 pag.). Prom./coprom.: Prof.dr.ir. J. Huskens & Dr. P. Jonkheijm.
Groenland, A.W. (2011, July 08). Nanolink-based thermal devices: integration of ALD TiN thin
films. University of Twente (157 pag.). Prom./coprom.: Prof.dr.ir. R.A.M. Wolters & A.Y. Kovalgin.
Gu, H. (2011, March 18). Controlling two-phase flow in microfluidic systems using
electrowetting. University of Twente (128 pag.). Prom./coprom.: Prof.dr. F. Mugele & Dr. M.H.G.
Duits.
Hildenbrand, N. (2011, June 10). Improving the electrolyte-cathode assembly for mt-SOFC.
University of Twente (157 pag.). Prom./coprom.: Prof.dr.ing. D.H.A. Blank & Dr. B.A. Boukamp.
Hoeve, W. van (2011, March 23). Fluid dynamics at a pinch: droplet and bubble formation in
microfluidic devices. University of Twente (128 pag.). Prom./coprom.: Prof.dr. D. Lohse.
Hosseiny, S.S. (2011, July 15). Vanadium / air redox flow battery. University of Twente (163
pag.). Prom./coprom.: Prof.dr.-ing. M. Wessling.
Izadi, N. (2011, January 07). Bio-inspired MEMS Aquatic Flow Sensor Arrays. University of
Twente (246 pag.). Prom./coprom.: Dr.ir. G.J.M. Krijnen.
Jani, J.M. (2011, December 02). Multiphase membrane contactors and reactors. University of
Twente (152 pag.). Prom./coprom.: Prof.dr.ir. R.G.H. Lammertink & Prof.dr.-ing. M. Wessling.
Jose, S. (2011, December 13). Reflector stack optimization for Bulk Acoustic Wave resonators.
University of Twente (129 pag.). Prom./coprom.: Prof.dr. J. Schmitz & Dr.ir. R.J.E. Hueting.
Karminskaya, T. (2011, February 16). Theory of Josephson effect in junctions with complex
ferromagnetic/normal metal weak link region. University of Twente (119 pag.). Prom./coprom.:
Prof. H. Rogalla & Dr. A. Golubov.
Koelmans, W.W. (2011, June 17). Parallel Probe Readout. University of Twente (134 pag.). Prom./
coprom.: Prof.dr. M.C. Elwenspoek & Dr.ir. L. Abelmann.
Kopec, K.K. (2011, January 28). Charged porous membrane structures for separation of bio molecules.
University of Twente (155 pag.). Prom./coprom.: Prof.dr.-ing. M. Wessling & Dr. D. Stamatialis.
Kottumakulal Jaganatharaja, R. (2011, June 29). Cricket Inspired Flow-Sensor Arrays.
University of Twente (187 pag.). Prom./coprom.: Dr.ir. G.J.M. Krijnen.
Kulve te, H. (2011, April 21). Anticipatory interventions and the co-evolution of nanotechnology
and society. University of Twente (263 pag.). Prom./coprom.: Prof.dr. A. Rip.
Lamprecht, T. (2011, June 23). Embedded Micro-Mirrors for Compact Routing of Multimode
Polymer Waveguides. University of Twente (137 pag.). Prom./coprom.: Prof.dr. M. Pollnau.
Lee, J.S. (2011, May 20). Biodegradable polymersomes for drug delivery. University of Twente
(166 pag.). Prom./coprom.: Prof.dr. J. Feijen.
Lu, Jiwu (2011, June 22). Solar Cells on CMOS Chips as Energy Harvesters. University of Twente
(117 pag.). Prom./coprom.: Prof.dr. J. Schmitz & Dr. A.Y. Kovalgin.
Mampallil Augustine, D. (2011, September 22). Microfluidic flow driven by electric fields.
University of Twente (175 pag.). Prom./coprom.: Prof.dr. F. Mugele & Dr. H.T.M. van den Ende.
Manukyan, G. (2011, September 16). Electrical manipulation of liquids at interfaces. University
of Twente (109 pag.). Prom./coprom.: Prof.dr. F. Mugele & Prof.dr.ir. R.G.H. Lammertink.
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Martinez Mercado, J. (2011, July 15). Clustering and Lagrangian Statistics of Bubbles. University
of Twente (120 pag.). Prom./coprom.: Prof.dr. D. Lohse.
Masood, M.N. (2011, November 24). Surface modification of silicon nanowire field-effect devices
with Si-C and Si-N bonded Monolayers. University of Twente (134 pag.). Prom./coprom.: Prof.
dr.ir. A. van den Berg & E.T. Carlen.
Mikkenie, R. (2011, November 17). Materials Development for Commercial Multilayer Ceramic
Capacitors. University of Twente (200 pag.). Prom./coprom.: Prof.dr.ing. A.J.H.M. Rijnders & Dr.ir.
J.E. ten Elshof.
Odijk, M. (2011, March 04). Miniaturized electrochemical cells for applications in drug screening
and protein cleavage. University of Twente (181 pag.). Prom./coprom.: Prof.dr.ir. A. van den Berg
& Dr.ir. W. Olthuis.
Pacheco Benito, S. (2011, October 26). Carbon Nanofiber layers on Metal and Carbon Substrates.
University of Twente (134 pag.). Prom./coprom.: Prof.dr.ir. L. Lefferts.
Ploeg, S.H.W. van der (2011, May 11). Characterization of Multi Qubit Systems. University of
Twente (106 pag.). Prom./coprom.: Prof. H. Rogalla & Dr. A. Golubov.
Putten, E.G. van (2011, October 28). Disorder-Enhanced Imaging with Spatially Controlled Light.
University of Twente (112 pag.). Prom./coprom.: Prof.dr. A. Lagendijk & Dr. A.P. Mosk.
Roy, D. (2011, September 28). Characterization of electrical contacts for phase change memory
cells. University of Twente (131 pag.). Prom./coprom.: Prof.dr.ir. R.A.M. Wolters.
Ruggi, A. (2011, June 10). Tuning brightness and oxygen sensitivity of Ru(II) and Ir(III) lumino phores.
University of Twente (177 pag.). Prom./coprom.: Prof.dr.ir. D.N. Reinhoudt & Dr. A.H. Velders.
Ruivenkamp, M. (2011, April 21). Circulating Images of Nanotechnology. University of Twente
(249 pag.). Prom./coprom.: Prof.dr. A. Rip.
Segerink, L.I. (2011, November 04). Fertility chip, a point-of-care semen analyser. University of
Twente (156 pag.). Prom./coprom.: Prof.dr.ir. A. van den Berg & Dr.ir. A.J. Sprenkels.
Shelley Egan, C. (2011, May 13). Ethics in practice: responding to an evolving problematic
situation of nanotechnology in society. University of Twente (168 pag.). Prom./coprom.: Prof.dr.
A. Rip & Dr. M. Kirejczyk.
Spasenovic, M. (2011, June 30). Surface plasmon polaritons and light at interfaces: propagating
and evanescent waves. University of Twente (130 pag.). Prom./coprom.: Prof dr. L. Kuipers &
Prof.dr. T.D. Visser.
Stawski, T.M. (2011, December 15). Understanding Microstructural Properties of Perovskite
Ceramics through Their Wet-Chemical Synthesis. University of Twente (152 pag.). Prom./
coprom.: Dr.ir. J.E. ten Elshof & Prof.dr.ing. D.H.A. Blank.
Steen, J-L.P.J. van der (2011, April 01). Geometrical scaling effects on carrier transport in
ultrthin-body MOSFETs. University of Twente (169 pag.). Prom./coprom.: Prof.dr. J. Schmitz, L.
Selmi & Dr.ir. R.J.E. Hueting.
Veen, P.J. de (2011, September 30). Interface Engineering for Organic Electronics; Manufacturing
of Hybrid Inorganic-Organic Molecular Crystal Devices. University of Twente (197 pag.). Prom./
coprom.: Prof.dr.ing. A.J.H.M. Rijnders & Prof.dr.ing. D.H.A. Blank.
Vereshchagina, E. (2011, December 09). Low-Power Silicon-based Thermal Sensors and
Actuators for Chemical Applications. University of Twente (135 pag.). Prom./coprom.: Prof.dr.
J.G.E. Gardeniers.
Yang, C. (2011, June 24). Photocatalytic CO2 Activation by Water. University of Twente (126 pag.).
Prom./coprom.: Prof.dr. G. Mul.
Yilmaz, M.D. (2011, June 09). Orthogonal supramolecular interaction motifs for functional
monolayer architectures. University of Twente (171 pag.). Prom./coprom.: Prof.dr.ir. J. Huskens.
Zhong, Z.C. (2011, October 12). Instability, the driving force for new physical phenomena.
University of Twente (111 pag.). Prom./coprom.: Prof.dr. P.J. Kelly.
Zhou, W. (2011, February 02). Proton-conducting solid acid electrolytes based upon
MH(PO3H). University of Twente (132 pag.). Prom./coprom.: Prof.dr.ir. A. Nijmeijer & Dr. H.J.M.
Bouwmeester.
Zijlstra, A.G. (2011, September 02). Acoustic Surface Cavitation. University of Twente (139 pag.).
Prom./coprom.: Prof.dr. D. Lohse.
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G. Catalan, A. Lubk, A.H.G. Vlooswijk, E. Snoeck, C. Magen, A. Janssens, G. Rispens, G. Rijnders,
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B. Gjonaj, J. Aulbach, P.M. Johnson, A.P. Mosk, L. Kuipers and A. Lagendijk, Active spatial control
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Ariando, X. Wang, G. Baskaran, Z.Q. Liu, J. Huijben, J.B. Yi, A. Annadi, A.R. Barman, A. Rusydi,
S. Dhar, Y.P. Feng, J. Ding, H. Hilgenkamp and T. Venkatesan, Electronic phase separation at the
LaAlO3/SrTiO3 interface, Nature Communications 2 (2011).
R. de la Rica, R.M. Fratila, A. Szarpak, J. Huskens and A.H. Velders, Multivalent Nanoparticle
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M. Bokdam, P.A. Khomyakov, G. Brocks, Z.C. Zhong and P.J. Kelly, Electrostatic doping of
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S.Y. Chen, J.G. Bomer, E.T. Carlen and A. van den Berg, Al2O3/Silicon NanoISFET with Near Ideal
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B.L.M. Hendriksen, F. Martin, Y.B. Qi, C. Mauldin, N. Vukmirovic, J.F. Ren, H. Wormeester,
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R. Truckenmuller, S. Giselbrecht, N. Rivron, E. Gottwald, V. Saile, A. van den Berg, M. Wessling
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H.C. Aran, D. Salamon, T. Rijnaarts, G. Mul, M. Wessling and R.G.H. Lammertink, Porous
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A.W. Maijenburg, E.J.B. Rodijk, M.G. Maas, M. Enculescu, D.H.A. Blank and J.E. ten Elshof,
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I. J. Minten, K.D.M. Wilke, L.J.A. Hendriks, J.C.M. van Hest, R.J.M. Nolte and J. Cornelissen, Metal-
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S. Ramachandra, Z.D. Popovic, K.C. Schuermann, F. Cucinotta, G. Calzaferri and L. De Cola,
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X.F. Sui, Q. Chen, M.A. Hempenius and G.J. Vancso, Probing the Collapse Dynamics of Poly(N-
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C.C. Wu, D.N. Reinhoudt, C. Otto, V. Subramaniam and A.H. Velders, Strategies for Patterning
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A. Ruggi, F.W.B. van Leeuwen and A.H. Velders, Interaction of dioxygen with the electronic
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M.A. Kostiainen, P. Ceci, M. Fornara, P. Hiekkataipale, O. Kasyutich, R. J. M. Nolte, J. Cornelissen,
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R. Osellame, H. Hoekstra, G. Cerullo and M. Pollnau, Femtosecond laser microstructuring: an
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R. de la Rica and A.H. Velders, Biomimetic Crystallization of Ag2S Nanoclusters in Nanopore
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A. Gomez-Casado, H.H. Dam, M.D. Yilmaz, D. Florea, P. Jonkheijm and J. Huskens, Probing
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E.M. Benetti, C. Acikgoz, X.F. Sui, B. Vratzov, M.A. Hempenius, J. Huskens and G.J. Vancso,
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M.R. Fitzsimmons, N.W. Hengartner, S. Singh, M. Zhernenkov, F.Y. Bruno, J. Santamaria,
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M.D. Leistikow, A.P. Mosk, E. Yeganegi, S.R. Huisman, A. Lagendijk and W.L. Vos, Inhibited
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Stability, Phys Rev Lett 106 (5) (2011).
J.R.T. Seddon, H.J.W. Zandvliet and D. Lohse, Knudsen Gas Provides Nanobubble Stability,
Phys Rev Lett 107 (11) (2011).
D.P.M. van Gils, S.G. Huisman, G.W. Bruggert, C. Sun and D. Lohse, Torque Scaling in Turbulent
Taylor-Couette Flow with Co- and Counterrotating Cylinders, Phys Rev Lett 106 (2) (2011).
E.G. van Putten, D. Akbulut, J. Bertolotti, W.L. Vos, A. Lagendijk and A.P. Mosk, Scattering Lens
Resolves sub-100 nm Structures with Visible Light, Phys Rev Lett 106 (19) (2011).
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[SCiEntiFiC PubliCAtionS]R. de la Rica and A.H. Velders, Supramolecular Au Nanoparticle Assemblies as Optical Probes
for Enzyme-Linked Immunoassays, Small 7 (1), 66-69 (2011).
A.W. Maijenburg, E.J.B. Rodijk, M.G. Maas, M. Enculescu, D.H.A. Blank and J.E. ten
Elshof, Hydrogen Generation from Photocatalytic Silver|Zinc Oxide Nanowires: Towards
Multifunctional Multisegmented Nanowire Devices, Small 7 (19), 2709-2713 (2011).
I.J. Minten, K.D.M. Wilke, L.J.A. Hendriks, J.C.M. van Hest, R.J.M. Nolte and J. Cornelissen, Metal-
ion-induced formation and stabilization of protein cages based on the cowpea chlorotic mottle
virus, Small 7 (7), 911-919 (2011).
S. Ramachandra, Z.D. Popovic, K.C. Schuermann, F. Cucinotta, G. Calzaferri and L. De Cola,
Förster Resonance Energy Transfer in Quantum Dot–Dye-Loaded Zeolite L Nanoassemblies,
Small 7 (10), 1488-1494 (2011).
X.F. Sui, Q. Chen, M.A. Hempenius and G.J. Vancso, Probing the Collapse Dynamics of Poly(N
-isopropylacrylamide) Brushes by AFM: Effects of Co-nonsolvency and Grafting Densities,
Small 7 (10), 1440-1447 (2011).
C.C. Wu, D.N. Reinhoudt, C. Otto, V. Subramaniam and A.H. Velders, Strategies for Patterning
Biomolecules with Dip-Pen Nanolithography, Small 7 (8), 989-1002 (2011).
R. Arayanarakool, L.L. Shui, A. van den Berg and J.C.T. Eijkel, A new method of UV-patternable
hydrophobization of micro- and nanofluidic networks, Lab on a Chip 11 (24), 4260-4266 (2011).
W. Browne, J.M. Gordillo, J. Hussong, M. Kreutzer, D. Lohse, F. Mugele, P. Onck, N. Schorr and A.
van den Berg, Contributors to the Netherlands issue, Lab on a Chip 11 (12), 1993-1994 (2011).
E. Castro-Hernandez, W. van Hoeve, D. Lohse and J.M. Gordillo, Microbubble generation in a
co-flow device operated in a new regime, Lab on a Chip 11 (12), 2023-2029 (2011).
C. Dongre, J. van Weerd, G.A.J. Besselink, R.M. Vazquez, R. Osellame, G. Cerullo, R. van
Weeghel, H.H. van den Vlekkert, H. Hoekstra and M. Pollnau, Modulation-frequency encoded
multi-color fluorescent DNA analysis in an optofluidic chip, Lab on a Chip 11 (4), 679-683 (2011).
H. Hardelauf, J. Sisnaiske, A.A. Taghipour-Anvari, P. Jacob, E. Drabiniok, U. Marggraf, J.P.
Frimat, J.G. Hengstler, A. Neyer, C. van Thriel and J. West, High fidelity neuronal networks
formed by plasma masking with a bilayer membrane: analysis of neurodegenerative and
neuroprotective processes, Lab on a Chip 11 (16), 2763-2771 (2011).
L.I. Segerink, A.J. Sprenkels, J.G. Bomer, I. Vermes and A. van den Berg, A new floating
electrode structure for generating homogeneous electrical fields in microfluidic channels,
Lab on a Chip 11 (12), 1995-2001 (2011).
Y.B. Xie, J.D. Sherwood, L.L. Shui, A. van den Berg and J.C.T. Eijkel, Strong enhancement of
streaming current power by application of two phase flow, Lab on a Chip 11 (23), 4006-4011
(2011).
F. Ay, I. Inurrategui, D. Geskus, S. Aravazhi and M. Pollnau, Integrated lasers in crystalline
double tungstates with focused-ion-beam nanostructured photonic cavities, Laser Physics
Letters 8 (6), 423-430 (2011).
VISIT OUR WEBSITE (WWW.UTWENTE.NL/MESAPLUS/PUBLICATIONS) FOR THE COMPLETE
PUBLICATION LIST.
Patents
L.I. Segerink, A.J. Sprenkels, M.J. Koster, A. van den Berg, “Compact 2D fluorescence
detection system for on-chip analysis”, 61/483,900.
K. van der Maaden, J.A. Bouwstra, W. Jiskoot, N. Tas, “Method to coat an active agent to a
surface”, N2007382, 9 Sept. 2011.
S. Le Gac, V.C. Stimberg, A. van den Berg, “A method for preparing a microfluidic device
comprising a series of bilayer lipid membrane sections”, 2007354, 5 Sept. 2011.
Rottenberg, X., Jansen, H.V., Tilmans, H.A.C. & De Raedt, W.”Switchable capacitor”, EP1398811,
10 Aug. 2011.
Volker, A.W.F., Blokland, H., Velthuis, J.F.M. & Lotters, J.C., “Fluid flow meter using thermal
tracers”, EP2100105, 12 Jan. 2011.
Dutczak, S.M., Cuperus, D.F. & Stamatialis, D. “Crosslinked polyimide membrane”, EP 11171318.6.
MESA+ AnnuAl REpoRt 2011
ANNUALREPORT 2011
Mesa+ Governing board Dr. G.J. Jongerden - Managing Director Exergy
Prof. dr. ir. A.J. Mouthaan - Dean Faculty of Electrical Engineering, Mathematics and Computer Science
Ir. J.J.M. Mulderink - Consultant Sustainable Technology
Dr. A.J. Nijman - Director Research Strategy & Business Development Philips NatLab
Prof. dr. J.A. Put - Director Performance Materials DSM Research
Dr. J. Schmitz - Vice President, Manager Process Technology Lab NXP Semiconductors
Prof. dr. G. van der Steenhoven - Dean Faculty Science & Technology
Mesa+ scientific advisory board Dr. J.G. Bednorz - IBM Zurich Research Laboratory, Switzerland
Prof. H. Fujita - University of Tokyo, Japan
Prof. M. Möller - Rheinisch-Westfäische Technische Hochschule Aachen (RWTH), Germany
Prof. C.N.R. Rao - Jawaharlal Nehru Centre for Advanced Scientific Research, India
Dr. H. Rohrer - IBM Zürich Research Laboratory, Switzerland
Prof. F. Stoddart - University of California, USA
Prof. E. Thomas - Massachusetts Institute of Technology (MIT), USA
Prof. E. Vittoz - Swiss Center for Electronics and Microtechnology (CSEM), Switzerland
Prof. G. Whitesides - Harvard University, USA
Mesa+ Management Prof. dr. ing. D.H.A. Blank - Scientific Director
Ir. M. Luizink - Technical Commercial Director
Contact details MESA+ Institute for Nanotechnology
University of Twente, P.O. Bo 217, 7500 AE Enschede, the Netherlands
+ 31 53 489 2715, [email protected], www.utwente.nl/mesaplus
MESA+ Governance Structure[About MESA+]
colophon Editing: MESA+ Institute for Nanotechnology, Miriam Luizink, Annerie van Steijn-Heesink I Design: WeCre8 Creatieve Communicatie, Enschede,
the Netherlands I Photography: Eric Brinkhorst, Martin Bosker (Slightly Tilted) I Printed by: DeltaHage, The Hague, the Netherlands.
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