international winterschool on bioelectronics bioel2014 · considered or investigated include...
TRANSCRIPT
International Winterschool
on Bioelectronics BioEl2014
Kirchberg in Tirol,
Austria
February 22nd - March 1st, 2014
Program and book of abstracts
www.BioEl.at
Sa
turd
ay,
Feb
ruary
22
nd
Su
nd
ay,
Feb
ruary
23
rd
Mo
nd
ay,
Feb
ruary
24
rd
Tu
es
da
y,
Feb
ruary
25
th
We
dn
esd
ay,
Feb
ruary
26
th
Th
urs
da
y,
Feb
ruary
27
th
Fri
day,
Feb
ruary
28
th
Sa
turd
ay,
Ma
rch
1st
7:3
0-8
:30
Arr
iva
l D
ay
Bre
akfa
st
Bre
akfa
st
Bre
akfa
st
Bre
akfa
st
Bre
akfa
st
Bre
akfa
st
Bre
akfa
st
Chair:
Mere
dith
C
hair:
Irim
ia-V
ladu
Chair:S
arikaya
Chair:
Fa
rin
ola
C
hair:
Berg
gre
n
Chair:
Resel
8:3
0 –
9:3
0
Grü
ne
r S
ari
ka
ya
Me
red
ith
In
ga
nä
s
Ro
lan
di
Grü
ne
r D
ep
art
ure
Da
y
9:3
0-1
0:0
0
1.
Cho
rtos
2.
Dum
itru
1
. Z
apf
2.
Dig
en
na
ro
1.
Ma
str
op
asq
ua
2
. S
che
rwitzl
1.
Arm
ga
rth
2.
Re
se
l 1
. B
an
din
i 2
. K
östle
r 1
. L
ato
ne
n
2.
Vo
na
10:0
0-1
0:3
0
Coff
ee
Bre
ak
Coff
ee
Bre
ak
Coff
ee
Bre
ak
Coff
ee
Bre
ak
Co
ffe
e B
rea
k
Co
ffe
e B
rea
k
10:3
0-1
1:3
0
Ste
ckl
Gro
te
Be
rgg
ren
Hü
ble
r V
ele
v
Bis
ca
rini
11:3
0-1
2:0
0
1.
Ree
de
r 2
. C
am
pa
na
1.
Lam
pre
ch
t 2
. A
nto
he
1.
Ko
fle
r 2
. S
imo
n
1.
Pe
tte
rsso
n
2.
Casta
gno
la
1.
Pa
ch
eco
2.
Schm
oltn
er
1.
Schla
ge
r 2
. S
ima
ite
12:0
0-1
7:3
0
Scie
ntific
dis
cu
ssio
ns, fr
ee
-fo
rm m
ee
tin
gs
Scie
ntific
dis
cu
ssio
ns, fr
ee
-fo
rm m
ee
tin
gs
Scie
ntific
dis
cu
ssio
ns, fr
ee
-fo
rm m
ee
tin
gs
Scie
ntific
dis
cu
ssio
ns, fr
ee
-fo
rm m
ee
tin
gs
Scie
ntific
dis
cu
ssio
ns, fr
ee
-fo
rm m
ee
tin
gs
Scie
ntific
dis
cu
ssio
ns, fr
ee
-fo
rm m
ee
tin
gs
17:3
0-1
9:0
0
Din
ne
r
Din
ne
r D
inn
er
Din
ne
r D
inn
er
Din
ne
r
Chair:
Solin
C
hair:
Ste
ckl
Chair:
Leonat
19:0
0-2
0.0
0
F
ari
nola
Irim
ia-V
lad
u
P
oste
r sessio
n
Ka
lte
nb
run
ne
r
Pa
ne
l D
iscu
ssio
n:
Org
an
ic
Cyb
ern
etics
„Bauernbuffet”
(f
estive
fin
al
din
ne
r in
tr
ad
itio
nal
Tir
ole
an
sty
le)
20.0
0-2
0.3
0
1
. S
chm
id
2.
Fia
n
1.
Cifa
relli
2
. A
pa
yd
in
20.3
0-
Welc
om
e +
Win
e
Re
d =
tuto
rial ta
lk
Blu
e =
co
ntr
ibu
ted
ta
lk
Ye
llow
= g
rou
p e
ve
nt
White
= F
ree
tim
e
2
International Winterschool
on Bioelectronics BioEl2014
Kirchberg in Tirol,
Austria Bio-compatible, bio-integrated, bio-inspired materials and devices
www.BioEl.at
February 22nd - March 1st, 2014
THE ORGANIZING COMMITTEE:
Chair: Eric Daniel Głowacki, Johannes Kepler Universität Linz, Austria
Members: Niyazi Serdar Sariciftci, Johannes Kepler Universität Linz, Austria
Helmut Neugebauer, Johannes Kepler Universität Linz, Austria
Linz Institute for Organic Solar Cells, Johannes Kepler University Linz, Austria
Contact Address: [email protected] Conference website: www.bioel.at
3
Invited Tutorial Lectures - invited speakers:
Andrew Steckl, University of Cincinnati, USA
Arved Hübler, Chemnitz University of Technology, Germany
Fabio Biscarini, University of Modena, Italy
George Grüner, University of California, Los Angeles, USA
Gianluca Farinola, University of Bari, Italy
James Grote, US Air Force Research Labs, USA
Magnus Berggren, Linköping University, Sweden
Marco Rolandi, University of Washington, USA
Martin Kaltenbrunner, Tokyo University, Japan
Mehmet Sarıkaya, University of Washington, USA
Mihai Irimia-Vladu, Joanneum Research GmbH, Austria
Olle Inganäs, Linköping University, Sweden
Orlin Velev, North Carolina State University, USA
Paul Meredith, Queensland University, Australia
BioEl2014 is graciously sponsored by:
4
5
6
Oral Presentations
Sunday February 22nd
– Friday February 28th
7
The Bio-electronics Interface
G. Gruner
Department of Physics, University of California Los Angeles
Electric charge distributions and electrostatic interactions both within and between biomolecules play
a significant role in biology. These attributes also underlie the interactions between biomolecules and
electronic devices.
In the first lecture I will discuss (1) electronic sensing and monitoring devices and measurement
schemes, the information provided by such devices together with calibration issues (2) the interaction
of biomolecules with electronic devices and non-specific binding issues (3) monitoring interactions
between biomolecules, including ligand-receptor and antibody-antigen binding, and monitoring
enzymatic reactions and (4) our attempts to combine cell membranes with devices. I will also describe
our R/D efforts on PSA detection studies in physiological buffer.
The same devices can also serve, with bio-inspired recognition molecules as elements of an artificial
sensory system, an artificial eye, nose and tongue.
Sunday, 08:30 – 09:30
8
High Performance Sensors and Deformable Electronics for Health Monitoring
Technologies
Alex Chortosa, Zhenan Bao
b
aMaterials Science & Engineering Department, Stanford University, 496 Lomita Mall, Stanford, USA
bChemical Engineering Department, Stanford University, 381 N-S Mall, Stanford, USA
Constant monitoring of health indicators could give patients and healthcare professionals
unprecedented new diagnostic capabilities and advanced treatment options. Conformal
integration with a patient’s body could increase comfort, and requires devices that can flex
and stretch to minimize inhibition of the normal movements of the wearer. Extraction of
useful information requires improved sensor design for high sensitivity and easy readout. Our
group has been developing a range of technologies that could be applicable to bio-integrated
electronics, including high sensitivity pressure and temperature sensors, wireless sensors, and
deformable electronics. These technologies have additional potential applications in implanted
devices and other fields such as advanced robotics.
Capacitive pressure sensors have advantages of good sensitivity and low temperature
dependence. We have developed a method to microstructure the dielectric layer in capacitive
pressure sensors, leading to exceptionally high sensitivity, fast response time, and large signal
to noise ratios. The microstructured dielectric has been incorporated as the gate dielectric in
flexible organic transistors. The exceptionally high sensitivity and response speed of the
device surpassed previous reports and allowed the collection of high resolution pulse
waveform data that can be used to extract information about the stiffness of arteries. The
microstructured dielectrics have also been sandwiched between two inductive electrodes in
order to make a passive pressure sensor that can be interrogated using a high-frequency
wireless signal. The wireless devices could be made as small as one millimeter in diameter
and were sensitive enough to measure arterial pulse. The sensors were investigated for the
application of intracranial pressure monitoring in mouse brains.
Composites composed of a conductive filler in a polymer matrix have shown high sensitivities
to temperature, but these composites typically suffer from a lack of reproducibility. We have
shown that dispersing conductive fillers in a matrix of two crystalline polymers with different
melting points leads to exceptionally high sensitivity in a tunable range and stable sensing
characteristics. Furthermore, the composites were integrated into a wireless circuit, which
suggests potential compatibility with implanted devices.
Intrinsically stretchable transistors have been developed based on elastomeric substrates and
dielectrics, carbon nanotube (CNT) conductors, and organic and CNT-based semiconductors.
The devices can be robust enough to withstand sudden impacts, and stretch to over 200%
while maintaining functionality. The transistors could be implemented as readout circuitry for
bio-integrated, conformable sensors.
Sunday, 09:30 – 09:45
9
Smart gating solutions in EGOFET devices, for sensing applications
L. M. Dumitru,a, K. Manoli
a, M. Magliulo
a, G. Palazzo
a and L. Torsi
a
a Department of Chemistry , “Aldo Moro” University, Orabona 4, Bari, Italy
New bio-sensing platforms based on bio-recognition elements interfaced with
electronic devices were successfully developed in the last years. These smart devices,
capable of rapid screening of biological samples, have a high impact not only in point-of-
care applications but also in various analytical sectors.
High sensitivity and selectivity of electronic platforms can be achieved when a
biological receptor is incorporated onto the device. However, despite all efforts, is very
difficult to design and fabricate a relatively cheap, but reliable biosensor, that can offer
good sensitivity and selectivity (for gas or liquid sensing). Retaining the bioactivity of the
recognition element as well as the electrical property of the electronic transducer are
critical aspects for bioelectronics development and fabrication.
An Organic Field-Effect Transistor (OFET)1 can be used as electronic platform
interfaced with a solid electrolyte layer (EGOFET)2 or a biopolymer.
3 Previous studies
have demonstrated that polyelectrolyte brushes4 can be used for controlled protein
immobilization. Also, a number of biopolymers have the potential to be used either as
films, coatings or membranes that can be easily interfaced with bioelectronics devices.
In this work we report on the use of different polyelectrolyte layers or biopolymer
membranes, as gating materials, in direct contact with the organic semiconductor of an
EGOFET transducer. The investigated materials are water-soluble and the fabricated
device exhibited good electrical performance at voltages bellow – 1.
Figure 1. I-V curve of an poly(acrylic acid)(PAA) – based OFET (left) and bovine serum
albumin (BSA) adsorbed on a planar PAA brush (right).
1. Dumitru, L. M., Manoli, K., Magliulo, M., Sabbatini, L., Palazzo, G., Torsi, L. Plain Poly (acrylic acid)
Gated Organic Field-Effect Transistors on a Flexible Substrate ACS Appl. Mater. Interfaces 5, 10819-10823,
(2013).
2. Lars, H., Crispin, X., Robinson N. D., Sandberg, M., Hagel, O-J., Gustafsson, G., Berggren, M., Low-
Voltage Polymer Field-Effect Transistors Gated via a Proton Conductor Adv. Mater. 19, 97-101, (2007).
3. Plackett, D., Vimal, K. Biopolymers-New Materials for Sustainable Films and Coatings (John Wiley &
Sons, Ltd, 2011).
4. Hollmann, O., Claus C. Characterization of a planar poly (acrylic acid) brush as a materials coating for
controlled protein immobilization Langmuir, 22, 3300-3305, (2006).
Sunday, 09:45 – 10:00
10
Circuits on Cellulose: From Transistors to LEDs,
from Displays to Microfluidics on Paper
Andrew J. Steckl
Nanoelectronics Laboratory, University of Cincinnati
Cincinnati OH USA 45221-0030
[email protected] www.nanolab.uc.edu
Organic electronics is a rapidly growing field due to a combination of strong performance
from improving materials with the low fabrication cost associated with large area printing
technology. Recently, the incorporation into organic electronic technology of natural
biomaterials that are renewable and biodegradable is being increasingly investigated with the
goal of producing “green” electronics that is environment-friendly.
In this lecture I will review the use of cellulose-based paper as a material in a variety of
electronic (and related) applications, including transistors, light emitting diodes, displays,
microfluidics. Paper is a very attractive material for many device applications: very low cost,
available in almost any size, versatile surface finishes, portable and flexible. From an
environmental point of view, paper is a renewable resource and is readily disposable
(incineration, biodegradable). Applications of paper-based electronics1,2
currently being
considered or investigated include biochips, sensors, communication circuits, batteries, smart
packaging, electronic displays. The potential advantages of paper-based devices are in many
cases very compelling. For example, lab-on-chip devices fabricated on paper for bio/medical
applications3 use the capillary properties of paper to operate without the need of external
power sources, greatly simplifying the design and reducing the cost. Specific examples of
paper-based devices will be discussed, including organic light emitting diodes4 (OLED) and
field effect transistors5 (OFET) on flexible and transparent paper, medical diagnostic devices
utilizing lateral capillary flow on paper.
Organic electronic
devices fabricated on
paper:
left – OLED4
right – OTFT5
1. D. Tobjork and R. Osterbacka, “Paper electronics”. Adv Mater 23, 1935, doi:10.1002/adma.201004692
(2011).
2. A. J. Steckl, “Circuits on Cellulose”, IEEE Spectrum 50 (2) 48, doi:10.1109/MSPEC.2013.6420146 (2013).
3. Rolland, J. P. & Mourey, D. A. “Paper as a novel material platform for devices”, MRS Bulletin 38, 299,
doi:10.1557/mrs.2013.58 (2013).
4. S. Purandare, E. F. Gomez and A. J. Steckl, “High brightness phosphorescent organic light emitting diodes on transparent and flexible cellulose films”, IOP Nanotechnology, 25, (2014).
5. A. Zocco, H. You, J. A. Hagen and A. J. Steckl, “Pentacene organic thin-film transistors on flexible paper
and glass substrates”, IOP Nanotechnology, 25, (2014).
Sunday, 10:30 – 11:30
11
Conforming and Deploying Organic Transistors with Acute In Vivo Stability
Jonathan Reeder
a,b, Martin Kaltenbrunner
a,c, Taylor Ware
b, David E. Arreaga-Salas
b, Adrian
Avendano-Bolivarb, Tomoyuki Yokotaa,c
, Yusuke Inouea,c
, Masaki Sekinoa,c
, Walter Voitb,
Tsuyoshi Sekitania,c
and Takao Someyaa,c
a The University of Tokyo, Electrical and Electronic Engineering and Information Systems, 7-
3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan b The University of Texas at Dallas, Department of Materials Science and Engineering
800 W. Campbell Road, Richardson, Texas 75080-3021, USA c Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology
Agency (JST), 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
Future biomedical devices may enable chronic sensing or stimulation of body tissue through
stable interfaces between soft tissue and high-performance electronics. We demonstrate
flexible organic thin-film transistors (OTFTs) on physiologically-responsive smart polymer
substrates with shape-changing and softening properties. These devices can mechanically-
adapt when exposed to physiological conditions for creating soft bioelectronic interfaces,
while maintaining initial electrical properties. Additionally, deployable structures are
demonstrated with large geometry changes based on the release of stored applied stresses for
gripping 3D objects.
Shape memory polymers (SMPs) are smart polymers which respond to stimuli, such as a
temperature change, to soften and change shape. We synthesize SMP substrates based on
thiol-ene “click” chemistry with tunable thermomechanical properties, which enables a glass
transition (Tg) near body temperature. These substrates can adapt in vivo to autonomously
form secure interfaces with target tissue via a two order of magnitude drop in modulus when
exposed to physiological conditions, which reduces the modulus mismatch between the device
and soft tissue. Reduction in the mechanical mismatch between biomedical implants and soft
tissue through soft materials has been shown to extend the long-term viability of biotic/abiotic
interfaces.
Using a novel transfer-by-polymerization process, OTFTs are patterned on SMP substrates
enabling mechanically-adaptive OTFTs. We demonstrate acute in vivo stability of an OTFT
which adapts to the morphology of living soft tissue, with only small changes in device
performance after implantation for 24 hours. OTFTs fabricated on SMP substrates which are
reformed during polymerization can autonomously deploy into programmed 3D shapes from a
planar geometry to grip a cylindrical object. When heated above the substrate Tg, planar
OTFTs conform to 3D surfaces with radii as small as 2 mm. Flexural stability of the OTFTs is
demonstrated down to 1 mm radius for four bending configurations; with some devices
remaining operational at radii as small as 100 µm. The flexible low-voltage transistors (2 V)
based on the air-stable organic semiconductor, dinaphtho[2,3-b:2’,3’-f]thieno[3,2-b]thiophene
(DNTT), are demonstrated with a measured average mobility of 1.5 cm2V
-1s
-1 and an on/off
current ratio of 104, which is suitable for sensing small biosignals at low operating voltages.
Sunday, 11:30 – 11:45
12
Electrocardiographic recording with conformable organic electrochemical
transistor fabricated on resorbable bioscaffold
Alessandra Campana,a,b
Tobias Cramer,a Silvia Tortorella,
a,b Giulia Foschi,
d Daniel
Simonc, Magnus Berggren
c and Fabio Biscarini
d
a Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati
(CNR-ISMN), Via P. Gobetti 101, 40129 Bologna, Italy
bAlma Mater Studiorum-Università degli Studi di Bologna, Dipartimento di Chimica “G.
Ciamician”, Via Selmi 2, 40127, Bologna, Italy cDepartment of Science and Technology, Linköping University, SE-601 74 Norrköping,
Sweden dLife Science Dept., Università di Modena e Reggio Emilia, Via Campi 183, 41125
Modena, Italy
[email protected] [email protected]
Electrical signals govern in large part the functionality of our human body. Interfacing
them provides important means for medical diagnosis and therapy and is at the heart of
modern electroceutical treatments.1 New generations of implantable electroceuticals have
to be developed which combine the bioelectric medical activity with low invasiveness
during device implantation, operation and removal.2
In our contribution we present an
electrical transducer fabricated on a fully resorbable poly(L-lactic-co-glycolic) (PLGA)
thin film. A simple fabrication process is established which allows patterning of active
areas of the conducting polymer PEDOT:PSS contacted by gold electrodes on the
bioscaffold. Fast and sensible potentiometric sensing of the conformable biodegradable
and biocompatible device is demonstrated in physiologic solution. The recording of small
bioelectronic signals is demonstrated by measuring the electrocardiogram with the device
and the obtained signals are comparable to standard potentiometric measurements with
Faradaic electrodes. The work paves the way towards simple bioelectronic interfaces
processed on implantable bioscaffolds for recording and stimulation in muscular or
nervous tissue. a) Photograph of the
device showing its
transparency and
adaptability when
attached to human skin; b)
Wiring diagram of the
ECG recording
experiment; c) Measured
drain current trace (red)
as obtained during ECG
recording and comparison
to a normal potentiometric
recording with standard disposable leads (black).
This work was funded by the EU 7th
Framework Programme [FP7/2007-2013] under
Grant Agreement No. 280772, Implantable Organic Nanoelectronics (iONE-FP7) project
1. K. Famm, B. Litt, J. K. Tracey, E. S. Boyden, M. Slaoui, Nature 2013, 496, 159.
2. D. Khodagholy, T. Doublet, P. Quilichini, M. Gurfinkel, P. Leleux, A. Ghestem, E. Ismailova, T.
Hervé, S. Sanaur, C. Bernard, G. G. Malliaras, Nat. Commun. 2013, 4, 1575.
Sunday, 11:45 – 12:00
13
Building smart materials with electro/photo-active molecules and various
biological structures
Gianluca M. Farinola
Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, via Orabona 4,
70126 Bari, Italy
The lecture will present approaches to electro/photo-active architectures of different size
and function by covalent combination of conjugated molecules or polymers with various
biological structures.
The following examples will be discussed.
(1) Functionalization of semiconducting polymers with chiral small bio-molecules (e.g.
glucose, amino-acids, nucleosides). The
introduction of the enantiopure biological
moieties on the conjugated backbone enables
control of solid state organization1 and results
in organic semiconductors for high
performances electrical sensors.2
(2) Assembly of hybrid bio-organic
photoconverters by covalent decoration of the
photosynthetic Reaction Center (RC) of the
bacterium Rhodobacter sphaeroides R26 with
tailored organic dyes3 acting as antennas to
enhance the light harvesting capability of the
natural photosynthetic system.4
(3) Chemical or in vivo functionalization of the biosilica shells of diatoms microalgae
with conjugated organic molecules or stable radicals affording smart nanostructures.
The lecture will cover both synthetic aspects and properties of the resulting architectures,
focusing on the challenges of controlled combination of functional molecules and diverse
biological structures.
1. G. Pescitelli, O. Hassan Omar, A. Operamolla, G.M. Farinola, L. Di Bari Macromolecules 45, 9626-
9630 (2012).
2. L. Torsi, G.M. Farinola, F. Marinelli, M.C. Tanese, O. Hassan Omar, L. Valli, F. Babudri, F.
Palmisano, P. G. Zambonin, F. Naso Nature Mater. 7, 412-417 (2008).
3. A. Operamolla, R. Ragni, O. Hassan Omar, G. Iacobellis, A. Cardone, F. Babudri, G.M. Farinola Curr.
Org. Synth. 9, 764-778 (2012).
4. F. Milano, R.R. Tangorra, O. Hassan Omar, R. Ragni, A. Operamolla, A. Agostiano, G.M. Farinola, M.
Trotta Angew. Chem. Int. Ed. 51, 11019-11023 (2012).
Hybrid bio-organic photoconverters
Sunday, 19:00 – 20:00
14
Self-Assembled Peptide Nanostructures (SAPs) -
A Novel Platform for Biomolecular Electronics
Mehmet Sarikaya
GEMSEC, Genetically Engineered Materials Science and Engineering Center,
Departments of Materials Science & Engineering,
Chemical Engineering, and Oral Health Sciences
University of Washington, Seattle, WA, 98195, USA
[email protected]; http://www.GEMSEC.washington.edu
Protein-solid interactions and assembly of proteins on surfaces is utilized in many fields to
integrate intricate biological structures and diverse functions with engineered solid materials.
Examples include bioelectronics, biosensors, and bioimplants. In biology, proteins are the
major biopolymers that enable dynamic organic systems but they also catalyze mineralization,
growth, and intricate hard tissue formation with complex multifunctional properties. These are
all desirable merits in engineered systems but currently impossible to achieve. Controlling
proteins at bio-solid interfaces relies on establishing key correlations between primary
sequences and resulting interactions that follow spatial organizations on substrates. Using
combinatorial mutagenesis, similarity analysis in bioinformatics and rational design
principles, we can engineered short peptides
(7-25 amino acids long) by controlling their
folding patterns and, hence, tailoring the
molecular interactions that leads to a variety
of addressable self-assembled peptides (SAP)
nanostructures. The peptides are engineered
via simple point and domain mutations to
control fundamental interfacial processes,
including initial binding and molecular
recognition, surface aggregation and growth
kinetics, and intermolecular interactions.
Tailoring short peptides and their molecular
interactions offers versatile control over
molecular self-assembly, resulting in well-
defined surface properties essential in building engineered, chemically and electronically rich,
bio-solid interfaces. Peptides themselves and SAPs on solids, e.g., on single layer atomic
materials, form nanowires, nanoislands and confluent films, and have interesting transport
properties. As demonstrated, peptides alone, or in chimeric forms as bifunctional constructs
can be used to bridge nanosolids (nanoparticles, quantum dots and single layer atomic
materials) to form molecularly hybrid systems for a variety of biophotonics and bioelectronics
implementations. This tutorial will give an overview of the molecular biomimetics approaches
to peptide design and assembly on solids, recent advances in device implementations, and
provide future prospects in controlling bio/solid interfaces towards biomolecular electronics.
The research supported by a variety of USA agencies, including ARO, NSF (MRSEC &
BioMat) and NIH Programs (NCI), and WA-state LSDF.
Monday, 08:30 – 09:30
15
In vitro synthesis of LHCII-pigment complexes into polymeric membranes
Zapf Thomasa, Paulsen Harald
b, Geifman Shochat Susana
c, Sinner Eva- Kathrin
a
aDepartment of Nanobiotechnology, Laboratory for Synthetic bioarchitectures, University of
Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria
bInstitute of General Botany, University of Mainz, Müllerweg 6, 55099 Mainz, Germany
cDivision of Structural Biology & Biochemistry, Nanyang Technological University, 50
Nanyang Avenue, Singapore 639798
Despite decades of research some parts remains uncertain about photosynthesis, a process so
important and successful that the core structure of the light harvesting complexes has
remained unchanged throughout evolution. We present a novel approach to synthesize the
light harvesting complex II (LHCII), using a coupled transcription-translation cell-free wheat
germ extract system, and integrating it together with chlorophylls and carotenoids directly
into a biomimetic diblock-copolymer membrane system. This serves to enhance its stability
outside chloroplast membranes for in vitro studies. Polymeric bilayered vesicles called
polymersomes as well as polymer-palmitic acid bilayers formed from PBD(1200)-PEO(600)
from PBD(600)-PEO(450), either with or without chlorophyll extract derived from pea leaves.
Integration of the LHCII into the polymer vesicles and palmitic acid/polymer bilayers was
demonstrated by SPR, TEM, Western blotting and fluorescence measurements. Energy
transfer from chlorophyll b to chlorophyll a was observed indicating that the LHCII had
assumed a native conformation and function within the polymer membrane. The successful
integration of LHCII-pigment complexes into polymeric membranes opens the possibility for
technological usage of LHCII.
Figure 1: Basic principle of LHCII in vitro synthesis into polymersomes. A wheat germ
extract is used for a coupled transcription and translation of LHCII into polymersomes in the
presence of chlorophylls and carotenoids.
Monday, 09:30 – 09:45
16
Self-organizing Amino Acid-Functionalized Oligothiophenes
Angela Digennaroa, Helma Wennemers
b, Sylvia Schmid
a, Elena Mena-Osteritz
a, Peter
Bäuerlea
aInstitute of Organic Chemistry II and Advanced Materials, University of
Ulm, Albert-Einstein-Allee 11, D-89081 Ulm, Germany b
Department of Organic Chemistry, ETH Zürich, Wolfgang Pauli Strasse 10,
CH-8093 Zürich, Switzerland
Oligo- and polythiophenes are an attractive class of organic semiconducting materials, which
have received considerable attention for the development of organic electronic devices, such
as field-effect transistors (FETs) or solar cells.1 Since the performance of such organic devices
has been found to be strongly influenced by the supramolecular organization of the
conjugated systems, we combined non-polar oligothiophenes with polar amino acids, e.g.
proline, which should lead to hybrids capable of self-assembly via various non covalent
interactions such as van-der-Waals forces, H-bonding and π-stacking.
The hybrids we present consist of an -alkylated quaterthiophene, as conjugated backbone,
and a protected proline, as bio motif.
The chiral (2S,4S)- and (2R,4R)-monoproline-quaterthiophene hybrids were synthesized by
Cu(I)-catalysed 1,3-dipolar Huisgen cycloaddition. The self-organization was investigated in
solution (CD-/UV-Vis–spectroscopy) and in the solid state (TEM and AFM). It could be
shown by chiroptical spectroscopy that the enantiomerically pure compounds aggregate into a
helical superstructure.2
1. A. Mishra, C.-Q. Ma, P. Bäuerle, Chem. Rev. 2009, 109, 1141-1276; b) R. D. McCullough, Adv. Mater.
1998, 10, 93-116; c) A. Schenning, E. W. Meijer, Chem. Commun. 2005, 3245-3258.
2. A. Digennaro, H. Wennemers, G. Joshi, S. Schmid, E. Mena-Osteritz and P. Bäuerle, Chem. Commun.,
2013, 49 (93), 10929 - 10931
Monday, 09:45 – 10:00
17
Biotronics
Biopolymers for Electronics and Photonics
Fahima Ouchena,b
, Perry Yaneya,c
, Emily Heckmana, Carrie Bartsch
a, James Grote
a
aAir Force Research Laboratories, Wright-Patterson Air Force Base, Ohio, USA
bUniversity of Dayton Research Institute, Dayton, Ohio, USA
cDepartment of Physics, University of Dayton, Dayton Ohio, USA
Biotronics is the development and implementation of a new class of polymers that possess
unique optical, electromagnetic and self-assembly properties that no other known polymers
have1. They have already demonstrated significant improvements in electronic and
optoelectronic device performance. These non-fossil fuel-based photonic and electronic
biopolymer materials, derived from deoxyribonucleic acid (DNA) biowaste, silk and
nucleobases are abundant, inexpensive and green materials that will not deplete our natural
resources or harm the environment. Since its inception, around 2000, this new field has
developed new biopolymers with low optical losses of < 0.5 dB/cm over a broad wavelength
range2, with tunable electrical conductivities 3-4 orders of magnitude higher than other
polymer materials with similar optical loss2 and tunable permittivities3. Their microwave
losses are also low, making them very attractive for high speed electro-optic devices4. Used as
cladding layers in nonlinear polymer-based electro optic modulators a significant reduction in
the overall optical insertion loss has been achieved, dropping from 15 dB to 10dB, a 3X
improvement5. Using DNA-based biopolymers for an electron-blocking layer in both
fluorescent and phosphorescent type organic light emitting diodes (OLEDs), a 3X increase in
efficiency has been demonstrated6. Using DNA-based biopolymers for the gate dielectrics in
organic field effect transistors (OFETs), nearly an order of magnitude lower gate voltage has
been achieved7. These all suggest significantly increased device efficiencies, higher outputs,
lower operating powers and longer lifetimes. This opens up a whole new field for
bioengineering, in addition to genomic sequencing and clinical diagnosis and treatment.
Where silicon is today’s fundamental building block for inorganic electronics and photonics,
biopolymers hold promise to become tomorrow’s fundamental building block for organic
photonics and electronics.
1. J. Grote, Journal of Nanphotonics, 2, (2008)
2. J. Grote, et. al., Journal of Physical Chemistry B, 108(25), pp. 8589-8591, (2004)
3. G. Subramanyam, et. al., IEEE Transactions on Nanobioscience, (2007)
4. C. Bartsch, et. al., Microwave and Optical Technology Letters, 49(6), pp. 1261-1265, (2007)
5. E. Heckman, et. al., Applied Physics Letters, 89, 181116, (2006)
6. J. Hagen, et. al., Applied Physics Letters, 88, 171109, (2006)
7. B. Singh, et. al., Journal of Applied Physics, 100, 024514, (2006)
Monday, 10:30 – 11:30
18
Optical sensor utilizing monolithically integrated organic photodiodes
B. Lamprecht, A. Tschepp, M. Cajlakovic, S. Köstler
JOANNEUM RESEARCH - Institute for Surface Technologies and Photonics, Franz-
Pichler Straße 30, A-8160 Weiz, Austria
We demonstrate a novel sensor type, which is based on the monolithic integration of
luminescent optical sensor spots together with thin-film organic photodiodes on one
substrate. Thereby we demonstrate a major advantage of organic semiconductor devices
over their inorganic counterparts – namely the possibility to manufacture organic devices
on almost arbitrary, user defined, substrates. To emphasize this we fabricated optical
sensors on planar as well as non-planar capillary substrates. In both cases the organic
photodiodes serve as integrated fluorescence detectors, simplifying the detection system
by minimizing the number of required optical components. The proposed concept enables
filter-less discrimination between excitation light and generated fluorescence light. The
functionality of the concept is demonstrated by an integrated oxygen sensor, exhibiting
excellent performance.
(Left) Schematic setup of a sensor, consisting basically of fluorescent sensor spots on top
and ring-shaped photodiodes on the backside of the substrate. The sensor spots are
excited by an OLED positioned below an aperture. (Right) Optical capillary sensor
based on the monolithic integration of fluorescent sensor layers and organic photodiodes
directly on a glass capillary.
A key advantage of the planar sensor geometry is the straightforward potential to realize
sensor arrays for the parallel detection of multiple parameters: different sensor spots are
illuminated by a common homogeneous large area light source, e.g. an OLED, and are
read-out by individual integrated organic photodiodes, surrounding the respective sensor
spots. The different sensor spots may utilize existing optical sensor schemes, which allow
to be transferred to this sensor platform.
The use of capillaries instead of planar substrates can lead to interesting new applications
in classical capillary sensor environments. Integration into established sensor setups
based on capillaries or tubes, such as e.g. pH glass electrodes, is possible. Furthermore
the favorable optical properties of tubes, especially their high light-collecting capability,
further the use of those components.
Monday, 11:30 – 11:45
19
Photovoltaic Structures Based on Biologic/Organic Thin Films Heterojunctions
of ITO/Chlorophyll a/TPyP/Al p-n Junction Cells
Ştefan Antohe
University of Bucharest, Faculty of Physics, Department of Electricity, Solid State Physics
and Biophysics, Atomistilor 405, P.O.Box: MG-11, 077125, Magurele-Ilfov, Romania,
In this paper the results obtained from the preparation and characterization of the p-n
heterojunction ITO/Chl-a/TPyP/Al photovoltaic cells. For these structures, Chl-a is the
microcrystalline chlorophyll-a used as biological semiconductor with p-type conductivity and
TPyP (5, 10, 15, 2O-tetra(4-pyrydil)21H, 23H-porphine) is an organic semiconductor with n-
type conductivity. The photovoltaic cells were prepared by electrochemical deposition of Chl-
a onto a glass substrate covered with conductive indium-tin oxide electrode (ITO), followed
by successive thermal vacuum deposition of TPyP layer and closing the structures by A1 top
electrode, also deposited by thermal vacuum evaporation technique. There are two advantages
offered by a two-layer biologic/organic p-n heterojunction as opposed to the single-layer
biologic or organic Schottky barrier type photovoltaic structures. In Schottky barrier cells the
illumination has to be transmitted through one of the two semitransparent metal electrodes
(preferably the rectifying electrode if the radiation is strongly absorbed) and thus almost half
of the available sunlight is lost. In the two-layer cell, one a hand, the illumination can be made
through a transparent, indium-tin oxide (ITO) electrode which forms an ohmic contact with
some organic dyes, and more importantly, the absorption characteristics of the two layers, if
complementary, enhance substantially the utilization of wavelengths of the solar spectrum by
the two-layer cell as compared with the one-layer cell. The studied current-voltage
characteristics in the dark and at illumination, of our ITO/Chl-a/TPyP/Al cells, together with
their action spectra, suggest the presence of a barrier at the Chla/TPyP interface, responsible
for the photovoltaic response. The typical parameters of a photovoltaic cells, measured under
two-layer cells were significantly improved with respect to those of single layer structures.
For example, the values of Uoc, Isc, ff, and power conversion efficiency of a p-n heterojunction
are larger than those for Chl-a based Schottky cells. Unfortunately, the higher internal
resistance of double layer structure strongly limits the power conversion efficiency, but the p-
n heterojunction of the ITO/Chl a/TPyP/Al photovoltaic cell with thinner Chl-a and TPyP
layers would be expected to be very useful for the technical improvement of hybrid
biologic/organic photovoltaic cells.
Monday, 11:45 – 12:00
20
“Green” Alternatives for Organic Electronics
Mihai Irimia-Vladua
a Joanneum Research Forschungsgesellschaft mbH, Franz-Pichler Str. Nr. 30, 8160 Weiz,
Austria
Organic electronics has a remarkable potential for the development of electronic products
that are non-toxic, environmentally friendly, and biodegradable. An ideal solution for the
production of such devices involves the fabrication of electronics either from natural
materials, or from materials that have been proved to be biodegradable or biocompatible.
Natural or nature-inspired small molecules dielectrics and semiconductors have been
recently successfully implemented in organic field effect transistors, and afforded
performances on par with state-of-the-art synthetic organic materials. Among the
materials we have exploited are naturally-occurring compounds like cellulose, shellac,
nucleic bases, various sugars, carotenoids, indigo and Tyrian purple, anthraquinone and
acridone derivatives, to name a few. We have demonstrated fully-biodegradable devices
and circuits featuring natural substrates, dielectric and semiconducting layers and showed
that the success of implementing these novel class of ‘green’ technologies to field effect
transistors could be successfully extended to organic photovoltaic field.
Figure 1: A symbolic concept of “green” technologies and their impact into our nowadays
Monday, 19:00 – 20:00
21
Bioinspired Oligothiophenes
Sylvia Schmid, Amaresh Mishra, Elena Mena-Osteritz, Peter Bäuerle*
Institute of Organic Chemistry II and Advanced Materials, University Ulm, Albert-Einstein-
Allee 11, D-89081 Ulm, Germany.
Oligo (OT)- and polythiophenes (PT) are among the best investigated organic materials
due to their outstanding optical and electronic properties and find versatile application in
electronic devices such as organic solar cells (OSCs) and organic field effect transistors
(OFETs).1 As the performance of such semiconducting devices depends directly on the
self-organization of the -conjugated materials, the formation of molecularly ordered
supra-structures is aspired.2 Covalent connection of OT-segments with structures of
biological relevance such as carbohydrates results amphiphilic hybrids capable to self-
assemble via various non-covalent interactions and to create a close interface between the
semiconducting particle and a specific cell-surface receptor. A series of carbohydrate-
functionalized linear and dendrimeric OT were synthesized using Sonogashira-cross-
coupling reaction and copper-catalyzed 1,3-dipolar cylcoaddition. Self-assembly
properties of the hybrids were investigated by UV-vis, fluorescence, CD–spectroscopy
and AFM experiments, and the specific binding to Concanavalin A was explored.
1. A. Mishra, C.-Q. Ma, P. Bäuerle Chem. Rev. 2009, 109, 1141-1276. 2. E. Mena-Osteritz, A. Meyer, B.M.W. Langeveld-Voss, R.A.J. Janssen, E.W. Meijer, P. Bäuerle Angew.
Chem. 2000, 112, 2792-2796.
Monday, 20:00 – 20:15
22
Large Area Organic Electronics: Challenges, Ecological Issues and Application
Examples
Alexander Fian,a Anja Haase,
a Herbert Gold,
a Dieter Nees,
a Mihai Irimia-Vladu,
a Barbara
Stadlober a
a Institute for Surface Technologies and Photonics, Joanneum Research
Forschungsgesellschaft mbH, Franz-Pichler-Straße 30, 8160 Weiz, Austria
Organic electronic devices such as organic thin film transistors (OTFTs), light emitting diodes
(OLEDs) and photo diodes have several advantages compared to silicon based devices.
Organic semiconductors and conductors enable technologies remarkable for low weight1,
flexibility and stretchability2 and allow the use of flexible substrates like plastic films, clothes
or even paper3. The production is less energy consuming due to the lower process
temperatures; the amount of process gases can be significantly reduced.
Nevertheless, the high potential of organic electronics was mainly demonstrated on
comparatively small area substrates or with low integration density. Large area production
techniques for high quality organic electronic circuits like roll-to-roll fabrication will provoke
completely new challenges. Especially, the exposure to chemicals used in the process chain
will increase dramatically and will require new strategies and ideas related to selection and
economical use of materials and supporting chemicals like solvents, photo- and imprint resists
or various additives. In this contribution we present a large area and roll-to-roll compatible
process scheme and first results for highly integrated organic thin film transistors and circuits.
We will discuss how EU-wide restrictions for hazardous materials and occupational health
and safety have to be considered and how natural source based and biodegradable materials
can be implemented in large area compatible fabrication of organic electronics.
Fig. 1: Roll-to-roll pilot line for the fabrication of large area organic electronics on
flexible substrates.
1. Forrest, S.R. The path to ubiquitous and low-cost organic electronic appliances on plastic. Nature
428, 911 (2004)
2. Sekitani, T. Zschieschang, U. Klauk, H. Someya, T. Flexible organic transistors and circuits with
extreme bending stability. Nature Mater. 9, 1015 (2010)
3. Lamprecht, B. Thünauer, R. Ostermann, M. Jakopic, G. & Leising, G. Organic photodiodes on
newspaper, Physica Status Solidi A 202, R50 (2005)
Monday, 20:15 – 20:30
23
Melanins: Natural Bioelectronic Materials?
Paul Meredith
Centre for Organic Photonics and Electronics, School of Mathematics and Physics,
University of Queensland, St Lucia Campus, Brisbane, Queensland, Australia QLD 4072
Melanins are a class of pigmentary macromolecules found throughout nature1. In humans,
they act as our primary photo-protective pigments in the skin, eyes and hair, but are also
found in the brain stem, inner ear and immune system. In these situations, we are not
completely clear as to their role and function. Melanins have been studied by biologists,
chemists and biophysicists for many years, and more recently have emerged as potential
bioelectronic materials because of a unique collection of physiochemical properties
including electrical conduction and photoconduction. In particular, our group has recently
demonstrated that eumlenin (the predominant form of the macromolecule) is a solid-state
“hybrid” conductor – it is capable of generating and sustaining ionic as well as electronic
currents. This physics is manifest in a strong dependence of the electrical properties upon
the state of hydration: dry eumelanin is an insulator, but the introduction of even small
amounts of water induces dramatic changes in electrical conduction (Figure 1)2. The
underlying mechanism responsible for this behaviour is associated with a local chemical
reaction whereby protons are released to be transported through the solvating water
matrix. We have recently speculated as to whether this may be a generic and potentially
very powerful feature in other macromolecules such as DNA which are similarly
hygroscopic and ionizable3. The ability of melanins to sustain and transduce between
electronic and ionic currents makes them an intriguing possibility for bioelectronic
interfaces3.
In my lecture I will discuss the basic properties of melanins, their functional roles and the
detailed origin of their electrical properties. I will describe our first results on melanin
“bioelectronic devices”, and in particular show how they could be used to transduce ion
and electronic currents at high fidelity. Melanins are very challenging materials to study,
but are potentially, the archetypal solid-state bioelectronic material.
1. Meredith, P. & Sarna, T. The physical and chemical properties of eumelanin. Pigment Cell
Research, 19(6), 572-594 (2006).
2. Mostert, A.B., Powell, B.J., Pratt, F.L., Hanson, G.R., Sarna, T., Gentle, I.R. & Meredith, P. Is
melanin a semiconductor: humidity induced self doping and the electrical conductivity of a
biopolymer. Proceedings of the National Academy of Sciences of the USA, 109(23), 8943-8947
(2012).
3. Meredith, P., Bettinger, C.J., Irimia-Vladu, M., Mostert, A.B. & Schwenn, P.E. Electronic and
optoelectronic materials and devices inspired by nature. Reports on Progress in Physics, 76,
034501 (2013).
4. Mostert, A.B., Powell, B.J., Gentle, I.R. & Meredith, P. On the origin of electrical
conductivity in the bio-electronic material melanin. APL, 100, 093701 (2012).
Tuesday, 08:30 – 09:30
24
Figure 1: The DC electrical conduction of solid-state eumelanin as a function of
hydration (Weight % Gained of water). In the dry state the material is strongly insulating
but as it becomes wet the conductivity increases rapidly due to a protonic mechanism. The
conventional Mott-Davis Amorphous Semiconductor Model (MDAS) does not adequately
explain this behaviour although apparently fits the conductivity isotherm if a sandwich-
electrode measurement geometry (a) is adopted. Mostert et al.4 have shown this is due to
non-equilibrium behaviour and is an experimental artifact. The true behaviour is
recovered if a surface contact geometry is adopted (b).
25
Chemical strategies for water processable melanin-like materials
M. Mastropasqua Talamo, a,c
S. R. Cicco, b A. Cardone,
b M. Ambrico,
c P. F. Ambrico,
c P.
Manini, d
A. Napolitano, d M. D’Ischia,
d G. M. Farinola
a
a Dipartimento di Chimica, Università degli Studi di Bari, v. Orabona 4 – 70125 – Bari (Italy)
b CNR-ICCOM U.O.S. di Bari, v. Orabona 4 – 70125 – Bari (Italy) c CNR-IMIP U.O.S. di Bari, v. Orabona 4 – 70125 – Bari (Italy)
d Dipartimento di Scienze Chimiche, Università degli Studi di Napoli, v. Cintia 4 – 80126 –
Napoli (Italy)
Melanins are promising materials for next-generation bio-inspired and bio-interfacing
electronics. Despite a persisting lack of knowledge about their precise chemical structure
and some technological issues such as their poor solution processability, melanins are
gaining the attention as bio-organic semiconductors, with possible applications spanning
from photovoltaics to signal transducing.1
A deeper structural analysis of melanin-like materials, as well as their effective
employment in electronic devices, demands for convenient approaches to thin film
deposition from solution. So far, the common route to melanin solution processing
requires strongly alkaline aqueous media, although strong basic conditions are known to
induce a partial degradation of the pigment chemical backbone. 2,3
A helpful expedient toward melanin-like homogeneous thin layers is offered by
polydopamines, which exhibit chemical resemblance with melanins, despite their different
synthetic origin. Polydopamines can be deposited onto a wide range of surfaces by simple
immersion of the substrates in a buffered solution containing the soluble precursors,
overcoming the issue of melanins’ insolubility and offering the opportunity of easily
tunable electrical properties. 4,5
On the other hand, we propose convenient functionalization with hydrophilic groups as an
interesting approach in the search of water-soluble melanin-like materials. In particular we
have studied the synthesis of a new water-soluble melanin based on the oxidative
polymerization of 5,6-dihydroxyindole units functionalized with triethyleneglycol chains.
Figure: The last step of the synthesis of a water-soluble melanin-like material.
1. D’Ischia M. et al. Angew. Chem. Int. Ed. 48, 3914-3921 (2009). 2. Ambrico M. et al. Org. Electron. 11, 1809-1814 (2009). 3. Ambrico M. et al. Adv. Mater. 23, 3332-3336 (2011). 4. Bell, V. et al, BioNanoSci. 2, 16-34 (2012). 5. Ambrico, M. et al., J. Mater. Chem. C 1, 1018-1028 (2013).
Tuesday, 09:30 – 09:45
26
Initial Film Growth Studies of Indigo on SiO2
Boris Scherwitzl,a Roland Resel,
a Adolf Winkler
a
a Institute of Solid State Physics, Graz University of Technology,
Petersgasse 16, 8010 Graz, Austria
Natural dyes have been used for thousands of years by ancient cultures in India, China and
Egypt to color textiles and food but have only been discovered recently as promising
semiconducting materials, attributable to the formation of hydrogen bonds and charge carrier
movements perpendicular to the growth direction.1 In this work adsorption and desorption
behavior, as well as film growth was studied in detail for indigo molecules on silicon dioxide.
The material was evaporated onto the substrate by means of physical vapor deposition under
ultra-high vacuum conditions and thin films were subsequently studied by Thermal
Desorption Spectroscopy, Auger Electron Spectroscopy, X-Ray Diffraction and Atomic Force
Microscopy. A comparison between sputter cleaned and carbon contaminated surfaces led to
differences in diffusion behavior and island growth. In the first case the substrate is reactive
and the indigo molecules form a strongly bonded wetting layer that does not desorb from the
surface in a temperature range of up to 800 K. Further adsorption led to a re-orientation of the
molecules and subsequently to a dewetting into islands. No wetting layer was observed on
contaminated surfaces, although the thermal desorption behavior looked very similar to the
one from sputter cleaned surfaces once the wetting layer formation is complete. Surface
morphology investigations on ultra-thin films (0.5 nm), performed ex-situ, suggest a very flat
wetting layer with islands of about 10 nm height nucleated on top. Thicker films (50 nm)
exhibit big differences in the island formation between sputter-cleaned and carbon
contaminated surfaces. Newly adsorbed molecules seem to have higher mobility across a
strongly bonded indigo layer compared to a simple carbon layer. All samples with mean film
thicknesses of more than 1 nm were stable under atmospheric conditions and did not show
any Ostwald ripening or material evaporation with time. The sticking coefficient was found to
be unity in all cases. Heat of evaporation calculations yielded desorption energies of
1.67±0.05 eV in the multilayer and 0.84±0.05 eV in the monolayer regime. The critical island
size in the aggregation regime was found to be 7.
AFM image for a 45 nm thick indigo film on a sputter-cleaned SiO2 substrate.
1. M. Irimia-Vladu, E.D.Glowacki, P.A. Troshin, G. Schwabegger, L. Leonat, D.K. Susarova, O. Krystal,
M. Ullah, Y. Kanbur, M.A. Bodea, V.F. Razumov, H. Sitter, S. Bauer, N.S. Sariciftci. Indigo – A Natural
Pigment for High Performance Ambipolar Organic Field Effect Transistors and Circuits. Adv. Materials 24, 375–
380 (2012).
Tuesday, 09:45 – 10:00
27
Organic Bioelectronics and Iontronics to Regulate Signaling in Cells,
in vitro and in vivo
Magnus Berggren
Laboratory of Organic Electronics, ITN, Linköping University, 601 74 Norrköping, Sweden
Conjugated polymers (CP) exhibit many desired properties that make them unique to translate
signals in between biology and electronics. CPs can be soft, flexible, can transport electronic
as well as ionic charge carriers, can also be included in hydrated composites and various
biological receptors can be introduced into the material via chemical synthesis. Various kinds
of organic bioelectronic devices have been constructed and studied aiming at regulating and
recording physiology and growth of biological systems.
Here, organic electrochemical devices will be reported targeting the regulation of cell growth
and signaling. In electronic surface switches, the outermost surface of areal or miniaturized
electrodes can be controlled via electrochemical switching. As the redox state is controlled,
the (in-)binding characteristics and conformation for proteins and other molecules are
dictated. This then triggers the onset or regulates the activity of matrix proteins etc. Based on
this principle various kinds of surface switches have been developed that can precisely
regulate the adhesion, spreading, growth, proliferation, differentiation and also release of cells
and tissues. The characteristic feature of those surface switches will be described along with a
review on various applications in which those have been explored. Specifically, surface
switches have been applied to control the growth stages of epithelial cells, thrombocyte
platelets and stem cells.
In ion bipolar membrane transistors (IBJT) and diodes (IBMD) the transport of charged
biomolecules can be controlled and regulated. In an array of different “iontronic” devices and
circuits, the IBJTs and IBMDs have been utilized to achieve well-defined and precise delivery
of neurotransmitters and ions to regulate physiology and signaling in cell systems. The
function and application of devices and circuits will be described. This “iontronic” technology
platform has been explored in various medical and biological applications, such as to regulate
the sensitivity of neuronal systems, specifically to control the sensitivity of the hearing system
and of the spinal cord.
1. A. Herland, K. M. Persson, V. Lundin, M. Fahlman, M. Berggren, E. W. H. Jager and A. I Teixeira,
Electrochemical Control of Growth Factor Presentation To Steer Neural Stem Cell Differentiation,
Angewandte Chemie International Edition, 50, 12529-12533 (2011).
2. K. Tybrandt, R. Forchheimer, M. Berggren, Logic gates based on ion transistors, Nature Communications, 3,
871 (2012).
3. K. Tybrandt, K. C. Larsson, A. Richter-Dahlfors and M. Berggren, Ion bipolar junction transistors, PNAS,
107, 9929-9932 (2010).
4. D. T Simon, S. Kurup, K. C. Larsson, R. Hori, K. Tybrandt, M. Goiny, E. W. H. Jager, M. Berggren, B.
Canlon and A. Richter-Dahlfors, Organic electronics for precise delivery of neurotransmitters to modulate
mammalian sensory function, Nature Materials, , 8, 742-746, (2009).
5. J. Isaksson, P. Kjäll, D. Nilsson, N. Robinson, M. Berggren and A. Richter-Dahlfors, Electronic Control of
Ca2+ Signalling in Neuronal Cells using an Organic Electronic Ion Pump, Nature Materials, 6, 673-679
(2007).
Tuesday, 10:30 – 11:30
28
Ion-selective Membranes as Key Components in Electrolyte-gated Organic
Field-Effect Transistors based Ion Sensors
J. Kofler,a K. Schmoltner,
a A. Klug,
a E. J. W. List-Kratochvil,
a,b
a NanoTecCenter Weiz Forschungsgesellschaft mbH, Franz-Pichler-Strasse 32, 8160 Weiz,
Austria; b
Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz,
Austria;
Electrolyte-gated field effect transistors (EGOFETs) are the transducers of choice when it
comes to the detection of ions or biological molecules in aqueous media. The crucial low-
voltage operation for a water-stable performance is ensured due to the formation of an
electric double layer at the electrolyte/organic semiconductor interface, exhibiting a very
high capacitance (on the order of ~1-10 µF). Based on this emerging EGOFET
technology, we recently demonstrated for the first time an electrolyte-gated OFET for
selective and reversible detection of sodium ions.1 In order to obtain a sensitive and
selective response to Na+ we introduced an ion-selective membrane (ISM), being the key
component of such EGOFET ion sensors.
Within this context, the basic characterization of these ISMs and the corresponding
limiting factors for a proper combination with an EGOFET, will be discussed. Besides
presenting the general selective sensing mechanism of ISMs, the optimization as well as
the fabrication of a new pH sensitive ISM will be presented. On the way to a pH-sensor
for a broad detection range (pH 2 – pH 12) the challenges faced considering interfering
ions and large membrane potential changes will be discussed.
3D-printed measurement setup for the characterization of ion-selective EGOFETs.
1. Schmoltner, K., Kofler, J., Klug, A. & List-Kratochvil, E. J. W. Electrolyte-gated field effect
transistor for selective and reversible ion detection. Adv. Mater. 25 (47), 6895–6899 (2013).
Tuesday, 11:30 – 11:45
29
Full-wave rectification of ionic currents – unlimited electrochemistry?
Daniel T. Simon,a Erik O. Gabrielsson,
a Per Janson,
a Klas Tybrandt,
a Magnus Berggren
a
a Laboratory of Organic Electronics, Dept. of Science and Technology, Linköping University,
SE-601 74 Norrköping, Sweden
Iontronics is a new class of circuits and systems which operate on the flow of ions and
charged molecules rather than electrons.1-4
These systems represent a leap forward in
interfacing traditional electronics to biological systems, since they can translate between
the control hardware’s electronic fluxes, and the chemical fluxes of biological signaling.
This translation of signals is typically achieved electrochemically by cycling redox-active,
often organic electronic, electrodes through changes in voltage, and utilizing the resulting
chemical products as the iontronic signal carriers. For example, oxidation of the familiar
PEDOT:PSS in electrolyte results in the liberation of cations as iontronic carriers.5 The
problem with this method is that the electrodes, and thus the source of reliably controlled
ion flux, is limited by electrochemical capacity, i.e., the volume of material available to be
reduced or oxidized. AC signaling, i.e., sequential oxidation and reduction cycles of the
electrodes, can circumvent this electrode limitation. However, steady DC ion currents are
still required for the iontronic circuitry. The solution is an ion current rectifier. In this
presentation, we detail our development of such a device, built of interconnected ion
bipolar membrane diodes (IBMDs).6 As with conventional diode bridges, the circuit can
be used for full-wave rectification of ionic currents. Furthermore, the IBMDs are
constructed of cation- or anion-selective materials, meaning that the ionic currents are
rectified for flow in a single direction. This results in charge equivalence between the
driving electronic signals and the resulting ion fluxes, and thus precisely controlled ion
transport. We will present the ion diode bridge architecture first as a full-wave rectifier,
and then as a charged neurotransmitter delivery device not limited by electrode capacity.
Finally, we will discuss the ion diode bridge’s implication both as a demonstration of new
iontronic circuitry, and as a long-term delivery component for implantable therapeutics.
1. Tarabella, G. et al. New opportunities for organic electronics and bioelectronics: ions in action.
Chemical Science 4, 1395–1409 (2013).
2. Malliaras, G. G. Organic bioelectronics: A new era for organic electronics. Biochimica et Biophysica
Acta 1830, 4286–4287 (2013).
3. Berggren, M. & Richter-Dahlfors, A. Organic Bioelectronics. Advanced Materials 19, 3201–3213
(2007).
4. Leger, J., Berggren, M., and Carter, S. A. (eds.) Iontronics. (CRC Press Boca, Raton, FL, 2010).
5. Isaksson, J. et al. Electronic control of Ca2+
signalling in neuronal cells using an organic electronic ion
pump. Nature Materials 6, 673–679 (2007).
6. Gabrielsson, E. O., Tybrandt, K. & Berggren, M. Ion diode logics for pH control. Lab on a Chip 12,
2507–2513 (2012).
Tuesday, 11:45 – 12:00
Tuesday Poster session, 19:00 – (see abstracts after oral presentation abstracts)
30
Interfaces between biological systems and electronic polymers: from cell and
tissue to biological macromolecules and nanostructures
Olle Inganäs
Biomolecular and organic electronics, IFM, Linköpings Universitet, s 581 83 Linköping,
Sweden
Electronic and electroactive polymers offer new alternatives for electrical and mechanical
interfaces to biological cells and tissue. Our early development of electroactive polymer
microactuators for biomedicine 1,2
3,4
and neural electrodes for interfacing to neural
systems 5 demonstrated several of these options. Electronic polymers in contact with
biological macromolecules give photonic interfaces 6, where changes in absorption and
emission of light from these conjugated polyelectrolytes and oligoelectrolytes is used to
extract information on the different forms of biomolecules, in particular for protein
misfolding diseases. 7 Diagnostic probes of amyloid formation, one of the signs of
Alzheimer disease, eventually turn out to be of relevance for modifying the formation of
amyloids, with potential therapeutic value.
More recent work focus on the complexes formed between biological macromolecules and
metallic or semiconducting conjugated polyelectrolytes as nanostructures/ materials for
new devices and functions. PEDOT-S, a selfdoped metallic polymer, can be coordinated
to both protein and DNA. Electrochemical nanotransistors based on protein wires 8 or
DNA chains 9 are demonstrated, protein wires may be decorated or inserted with
electronic molecules and polymers 10
, and functional devices 11,12
may be modified by
inclusion of biomolecular nanostructures. 1) Smela, E.; Inganas, O.; Lundstrom, I.: Controlled Folding Of Micrometer-Size Structures. Science
1995, 268, 1735-1738.
2) Smela, E.; Inganas, O.; Pei, Q. B.; Lundstrom, I.: Electrochemical Muscles - Micromachining Fingers
And Corkscrews. Advanced Materials 1993, 5, 630-632.
3) Jager, E. W. H.; Smela, E.; Inganas, O.: Microfabricating conjugated polymer actuators. Science 2000,
290, 1540-1545.
4) Jager, E. W. H.; Inganas, O.; Lundstrom, I.: Microrobots for micrometer-size objects in aqueous media:
Potential tools for single-cell manipulation. Science 2000, 288, 2335-2338.
5) Nyberg, T.; Inganas, O.; Jerregard, H.: Polymer hydrogel microelectrodes for neural communication.
Biomedical Microdevices 2002, 4, 43-52.
6) Nilsson, K. P. R.; Inganas, O.: Chip and solution detection of DNA hybridization using a luminescent
zwitterionic polythiophene derivative. Nature Materials 2003, 2, 419-U10.
7) Herland, A.; Nilsson, K. P. R.; Olsson, J. D. M.; Hammarstrom, P.; Konradsson, P.; Inganas, O.:
Synthesis of a regioregular zwitterionic conjugated oligoelectrolyte, usable as an optical probe for
detection of amyloid fibril formation at acidic pH. Journal Of The American Chemical Society 2005,
127, 2317-2323.
8) Hamedi, M.; Herland, A.; Karlsson, R. H.; Inganas, O.: Electrochemical devices made from conducting
nanowire networks self-assembled from amyloid fibrils and alkoxysulfonate PEDOT. Nano Letters
2008, 8, 1736-1740.
9) Hamedi, M.; Elfwing, A.; Gabrielsson, R.; Inganas, O.: Electronic Polymers and DNA Self-Assembled
in Nanowire Transistors. Small 2013, 9, 363-368.
10) Solin, N.; Inganas, O.: Protein Nanofibrils Balance Colours in Organic White-Light-Emitting Diodes.
Israel Journal of Chemistry 2012, 52, 529-539.
11) Rizzo, A.; Solin, N.; Lindgren, L. J.; Andersson, M. R.; Inganas, O.: White Light with Phosphorescent
Protein Fibrils in OLEDs. Nano Letters 2010, 10, 2225-2230.
12) Rizzo, A.; Inganas, O.; Solin, N.: Preparation of Phosphorescent Amyloid-Like Protein Fibrils.
Chemistry-a European Journal 2010, 16, 4190-4195.
Wednesday, 08:30 – 09:30
31
Biofunctional Conducting Polymers for Tissue Engineering
Astrid Armgarth a,b,c
, Damia Mawad b,c
, Natalie Stingelin a,b
, Molly M. Stevens a,b,c,d
a Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, UK.
b Department of Materials, Imperial College London, London SW7 2AZ, UK.
c Department of Bioengineering, Imperial College London, London SW7 2AZ, UK.
d Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, UK.
There is a growing interest in engineering of sophisticated three-dimensional (3D)
conducting polymers (CP) tissue constructs that enables restoration of functionality in
damaged nerve, muscle or bone tissues, as these tissues respond to electrical stimulation.1-
3 While recent advances show high promise, including e.g. nanofibrous scaffolds and
biodegradable hydrogels comprised of CP or CP-composites, these constructs are not yet
clinically applicable.4-7
Current challenges involve the design and manufacture of CP
scaffolds that possess the appropriate biodegradability, biochemical motifs, as well as
mechanical and topological properties.7 My research addresses these needs by developing
improved methods towards biofunctionalized conducting polymers that can be processed
via chemical and/or physical approaches. We will present several functionalisation
schemes based on covalent conjugation of bioactive adhesion peptides to conducting
polymers via functional side groups. The use of covalent biofunctionalisation techniques
are an attractive means to control the stability of biological cues, as opposed to non-
covalently entrapped natural dopants that can easily be expelled from the systems by
continuous redox cycling or simply through leaching out by diffusion; thereby, reducing
both electroactivity and bioactivity of the constructs with usage.8 Additionally, the
generated schemes are also easily transferable to new systems, as demonstrated by
incorporation of different adhesion peptides. These materials are also not restricted with
regards to the techniques that can be used to process them into functional architectures, as
demonstrated by crosslinking of the conjugates to form novel 3D biofunctional-CP gels.
As a separate means to form multifunctional CP scaffolds, solid-state processing was
explored which resulted in mechanically robust and highly flexible platforms.
1. Gomez N, Chen S, Schmidt CE, J R Soc Interface. 4, (2007).
2. Mawad D, Stewart E, Officer D et al., Adv Funct Mater 113, (2012).
3. Cui H, Liu Y, Deng M et al., Biomacromol. 13, (2012).
4. Ku S, Lee S, Park C, Biomater. 33, (2012).
5. Huang H, Wu J, Lin X et al., Carbohydr Polym. 95, (2013).
6. Lee JY, Bashur CA, Goldstein AS et al., Biomater. 30, (2009).
7. Hardy J, Lee J, Schmidt CE, Curr Opin Biotechn. 24, (2013).
8. Stauffer W, Cui X. Biomater. 27, (2006)
Wednesday, 09:30 – 09:45
32
A Surface Induced Crystal Structure of 6,6’-dibromoindigo
R. Resel,a E. D. Głowacki,
b G. Schwabegger,
c A. Rizwan,
c C. Simbrunner, M. Irimia-Vladu
d
a Institute of Solid State Physics, Graz University of Technology, Austria
b Linz Institute for Organic Solar Cells, Johannes Kepler University Linz, Austria
c Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Austria
d Institute for Surface Technologies and Photonics, Joanneum Research Weiz, Austria
The crystallization of the molecule 6,6’-dibromoindigo (Tyrian Purple) is studied within
thin films. The films are prepared either by Hot Wall Epitaxy or by physical vapour
deposition. The deposition conditions are varied by using three different substrate surfaces
(thermally oxidized silicon, polyethylene and copper iodide) and different substrate
temperatures (50°C, 100°C and 150°C) during the deposition process. The morphology of
the films is studied by atomic force microscopy and by x-ray diffraction methods. Besides
the known crystal structure [1,2] of dibromoindigo an unknown crystal structure is
observed which can be assigned to a polymorph induced by the presence of a surface
during the crystallization process. The crystal structure is solved by indexing the x-ray
diffraction pattern and rigid body refinement using the experimentally observed structure
factors. A parallel stacking of the molecules is observed which is different to molecular
packing within the known crystal structure. This surface induced phase is present at all
surfaces and its appearance is suppressed at high substrate temperatures. The dominant
appearance of the phase at low substrate temperatures and the appearance with specific
preferred orientations of the crystallites at different surfaces suggests that this surface
induced phase is kinetically determined.
Reciprocal space maps of dibromo-indigo thin films prepared by Hot Wall Epitaxy (A)
and by physical vapour deposition (C). Solution of the crystal structures reveal either the
known crystal structure (B) or an unknown crystal structure induced by the presence of a
surface during the crystallisation process (D).
1. P. Suesse, C. Krampe, 6,6’-dibromo-indigo, the main component of Tyrian Purple. Its crystal structure
and light adsorption. Naturwissenschaften 66 (1979) 110.
2. S. Larsen, F. Wätjen; The Crystal and Molecular Structures of Tyrian Purple (6,6'-Dibromoindigotin)
and 2,2'-Dimethoxyindigotin. Acta Chemica Scandinavica A 34 (1980) 171-176.
Wednesday, 09:45 – 10:00
33
Printed Solar Cells on Paper — Alternatives for the Future Development
Arved C. Hübler
Institute for Print & Media Technology, Chemnitz University of Technology,
Reichenhainer Str. 70, 09126 Chemnitz, Germany
»… The advantage must go to those organisms whose
energy-capturing devices are most efficient …«
(Alfred Lotka1)
The energy supply of the mankind seems to be a key issue for today’s societies. On the
one hand, new technologies are required to solve the energy problem, on the other hand
different solutions are hotly debated, not only driven by rational sciences, but also by
believe and economic interest.
My group is working on printed solar cells on paper.2 For the further development of this
approach several options must be taken in account. Not only the primary technological
improvements as energy efficiency and lifetime are important, but also material costs,
production efficiencies, product concepts and usability and other topics play a roll.
Goal of this talk is to discuss some of the interdependencies between basic physical and
chemical restrictions and technical constrains related to the individual usage expectations
and the global environmental and economical setup. Some attention is paid to
methodological and conceptual problems and their actual perception.3,4
This contribution might be interesting not only for the solar energy discussion, but can be
seen as an example for the huddles of new technologies as printed electronics and printed
functionalities.
1. Lotka, Alfred J.: Contribution to the Energetics of Evolution; Proc. Nat. Acad. Sci. USA, Vol. 8 (1922)
p.147-154
2. Hübler, Arved; Trnovec, Bystrik; Zillger, Tino; Ali, Mozzam; Wetzold, Nora; Mingebach, Markus ;
Wagenpfahl, Alexander; Deibel, Carsten; Dyakonov; Vladimir: » Printed paper photovoltaic cells « ;
Advanced Energy Materials Vol 1/ 6, p. 1018–1022, Nov. 2011.
3. Raugei, Marco; Fullana-i-Palmer, Pere; Fthenakis, Vasilis: » The energy return on energy investment (EROI)
of photovoltaics: Methodology and comparisons with fossil fuel life cycles« ; Energy Policy Volume 45, June
2012, p. 576–582
4. Hoffmann, Manfred: » Perspektiven der Photovoltaik «; Physik Journal 13 (2014), p21-2
Wednesday, 10:30 – 11:30
34
Ion Modulated Transistors on Paper Using Phase Separated
Semiconductor/Insulator Blends
Fredrik Pettersson,a Janne Koskela,
b Tommi Remonen,
a,c Yanxi Zhang,
c Saara Inkinen,
c Roger
Bollström,d Anni Määttänen,
e Petri Ihalainen,
e Ari Kilpelä,
b Carl-Eric Wilén,
c Martti
Toivakka,d Jouko Peltonen,
e Ronald Österbacka
a
a Physics, Department of Natural Sciences, Åbo Akademi University, Porthaninkatu 3, FI-
20500 Turku, Finland b Electronics Laboratory, University of Oulu PL 4500 FI-90014 Oulu, Finland
c Polymer Technology, Department of Chemical Engineering, Åbo Akademi University,
Piispankatu 8, FI-20500 Turku, Finland d Paper Coating and Converting, Department of Chemical Engineering, Åbo Akademi
University, Porthaninkatu 3, FI-20500 Turku, Finland e Physical Chemistry, Department of Natural Sciences, Åbo Akademi University,
Porthaninkatu 3, FI-20500 Turku, Finland
We have built low voltage ion modulated transistors on paper and used these to construct
ring-oscillators that operate in the 5 Hz region (Figure 1a). Paper as such is a difficult
substrate to work with as it is porous and rough, but also because it contains OH-groups that
can chemically dope the semiconductor (SC). Creating a thin uniform SC film on such a
substrate can be difficult. We show that a thick SC film results in slow switching devices due
to a slow electrochemical doping of the SC during operation. The reason for this is the slow
movement of the ions penetrating the SC. This results in a higher source-drain current that is
dependent on the semiconductor thickness as the entire bulk is doped. The process is
reversible as the ions vacate the semiconductor as the gate bias is reversed.
To circumvent these obstacles we have utilized a blend of a SC and biodegradable polymer
insulator that spontaneously phase separates during the spin casting process. Due to the
different solubilities of the materials and their surface energies (including the paper substrate
and the atmosphere) involved, the insulator forms a layer on the bottom and the SC a layer on
top. The thickness of the SC layer will depend on the ratio of the blend. A transistor with a
thinner layer will have lower on-currents but doping and de-doping the SC during operation
will be fast resulting in a fast switching device. In Figure 1b) the rise times of transistors with
different ratios of SC/insulator blends have been plotted.
a) b)
Figure 1a) Rise times and gate leakage of transistors with different concentrations of
SC/insulator blend. b) Output of low concentration SC/insulator blend ring-oscillator.
Wednesday, 11:30 – 11:45
35
Flexible technology for PEDOT-modified neural probes
V. Castagnola,a,b
E. Descamps, a,b
C. Blatché, a,b
L.G. Nowak c and C. Bergaud
a,b
a CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France
b Univ de Toulouse, LAAS, F-31400 Toulouse, France
c Centre de Recherche Cerveau & Cognition (CerCo), UMR CNRS 5549, Toulouse, France
Implantable neural prosthetics devices offers a promising opportunity for the restoration
of lost functions in patients affected by brain or spinal cord injury, by providing the brain
with a non-muscular channel able to link machines to the nervous system. Nevertheless
current neural electrodes still suffer from high initial impedance and low charge-transfer
capacity because of their small-feature geometry.1,2
Furthermore, the chronic foreign body
reaction induced by initial trauma, micromotions, and device biocompatibility leads, after
a certain time, to the electrode encapsulation. The electrode/tissue interface plays a key
role for the achievement of the two critical requirements for neuroprosthetic device:
lifetime and biocompatibility.3
For this reason in our work we have developed
implantable microelectrodes that combine a flexible substrate with a conductive
polymer-modified electrode surface. We have validated a technological protocol for the
fabrication of structures based on Parylene C, using a silicon host support without the
need for a sacrificial layer. The gold electrode surface has been electrochemically
modified with Poly (3,4-ethylene) dioxythiophene (PEDOT) that has emerged as an
interesting candidate for neuroelectronic interfaces thanks to its excellent conductivity,4
stability and indications on its good biocompatibility. The coating is shown to be very
stable and resistant (as proven by the accelerated aging test), to largely decrease the
impedance and, as a consequence, the signal-to-noise ratio during stimulation and
recording of the brain activity. The so modified electrodes have been tested in vitro.
This figure shows our microelectrodes fabricated on Parylene substrate, the PEDOT
coating on the gold microelectrode surface and the “in vitro” biocompatibility and signal
achievement. 1. Abidian, M. R., Martin, D. C et al. Conducting-Polymer Nanotubes Improve Electrical Properties,
Mechanical Adhesion, Neural Attachment, and Neurite Outgrowth of Neural Electrodes, Small 3, 421–429,
(2010).
2. Cui X. and Zhou D., Poly(3,4-Ethylenedioxythiophene) for Chronic Neural Stimulation, IEEE transaction on
neural system and rehabilitation engineering, 15, 4, 502-508 (2007).
3. Kozai T., Kipke D. et al. Ultrasmall implantable composite microelectrodes with bioactive surfaces for
chronic neural interfaces, Nature Materials, 11, 1065-1073, (2012).
4. Castagnola V., Bayon C, Descamps E., Bergaud C., Morphology and conductivity of PEDOT layers produced
by different electrochemical routes, to be published on Synthetic Metals.
5 µm5 µm
a b
a
b
100 µm 30 µm 10 µm
Wednesday, 11:45 – 12:00
36
Imperceptible Plastic Electronics
Martin Kaltenbrunner,a,b
a The University of Tokyo, Electrical and Electronic Engineering and Information Systems, 7-
3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan b Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology
Agency (JST), 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan Department 2, University
The emerging field of conformable electronics places new physical requirements on electronic
components. Integration directly into or onto soft materials such as textiles or biological
tissues is of increasing interest for applications spanning medical, safety, security,
infrastructure, and communication industries among many others. The unique requirement
imposed in this field is that the electronics must be highly flexible in order to survive the
mechanical deformation of the malleable host material.
This talk introduces a technology platform for the development of large-area, ultrathin and
lightweight electronic and photonic devices, including organic solar cells, light emitting
diodes and active-matrix touch panels. Organic solar cells, less than 2 µm thick, endure
extreme mechanical deformation and have an unprecedented power output per weight of 10
W/g. Highly flexible, stretch-compatible polymer light emitting diodes for display
applications and ambient lightning conform to arbitrary 3D free-forms and provide electrical
functionality in yet unexplored ways through simple and cost-effective fabrication. Tactile
sensor arrays based on active-matrix organic thin film transistors weight only 3 g/m2 and can
be operated at elevated temperatures and in aqueous environments. For health care and
monitoring, such imperceptible sensing and actuating systems ensure the smallest possible
discomfort for patients. When transferred to a pre-stretched elastomer substrate, our ultrathin
electronic foils become ultra-compliant, withstanding mechanical stretching and relaxation
cycles to more than 400 % tensile strain repeatedly.
Imperceptible electronics: a) ultrathin and lightweight solar cells, b) active matrix sensor foil
as electronic skin, c) ultrathin, stretchable polymer OLEDs
Wednesday, 19:00 – 20:00
37
Growing Computer from Slime Mould
Angelica Cifarelli,a,b,
Alice Dimonte,a Tatiana Berzina,
a Victor Erokhin
a
a CNR-IMEM (National Council of the Researches – Institute of Materials for Electronics
and Magnetism), Parco Area delle Scienze 37A, 43124, Parma, Italy b Department of Physics and Earth Science, University of Parma, Viale Usberti 7A,
43124, Parma, Italy
Slime mould Physarum polycephalum is a single cell visible by an unaided eye. The slime
mould optimizes its network of protoplasmic tubes to minimize expose to repellents and
maximize expose to attractants and to make efficient transportation of nutrients. Its growth
implies a generation of electrical potentials and migration of ions due to the metabolism [1,2].
These properties of P. polycephalum, make it a priceless substrate for designing novel
sensing, computing and actuating architectures in living amorphous biological substrate [3,4].
The aim of the present work is the realization of deterministic adaptive network and spatial
distribution of nano and micro-scale materials and the combination of slime mold networks
with conducting polymer layers and electronic circuits using biocompatible interfaces.
The proposed approach is a step toward the utilization of adaptive abilities of P.polycephalum
for the information processing.
Figure Plasmodium of Physarum Polycephalum on paper towels.
1.Adamatzky, A. & Jones, J. On Electrical Correlates of Physarum Polycephalum Spatial Activity. Biophys.
Rev. Lett. 06, 29 (2011) DOI:10.1142/S1793048011001257
2. Whiting, J.G.H., de Lacy Costello B.P.J., Adamatzky,. A. Towards slime mould chemical sensor: Mapping
chemical inputs onto electrical potential dynamics of P.Polycephalum. Sens. Actuators B: Chem. 191, 844-
853.(2014) Online publication date: 1-Feb-2014.
3.Adamatzky, A., Armstrong, R., Jones, J., Gunji, Y.P.: On Creativity of Slime Mould. Int. J. General Syst. 42,
441-457(2013)
4. Adamatzky A., Erokhin V., Grube M., Schubert T., Schumann A. Physarum Chip Project: Growing
Computers From Slime Mould. Int J Unconventional Computing 8, 319—323(2012)
We acknowledge the financial support by the EU research project PhysarumChip (FP7 ICT Ref 316366).
Wednesday, 20:00 – 20:15
38
Direct Electrochemical Capture and Release of CO2 Using Nature Inspired
Pigments
D. H. Apaydin, E. D. Głowacki, E. Portenkirchner, N. S. Sariciftci
Linz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes
Kepler University Linz, Austria
Limiting anthropogenic carbon dioxide emissions constitutes a major issue faced by scientists
today. Technologies aim at capturing CO2, followed by sequestration or utilization. A key step
for both sequestration and utilization approaches of CO2 is controlled capture, storage and
release. Here we report an efficient way of controlled capture and release of carbon dioxide
using nature inspired, cheap, abundant and non-toxic pigments namely, Quinacridone and
Indigo. Electrochemically reduced electrodes having a structure ITO/Pigment (~100nm) are
capable of forming a Pigment·carbonate salt. Captured CO2 can be released both by heating or
by electrochemical oxidation. The amount of captured CO2 was quantified by FT-IR. The
uptake values for the thermal and electrochemical releases processes were 2.28 mmol/g and
4.61 mmol/g respectively. These values are among the highest reported uptake efficiencies
for electrochemical CO2 capture. For comparison, the state-of-the-art aqueous amine
industrial capture process has an uptake efficiency of ~8 mmol/g.
Wednesday, 20:15 – 20:30
39
Grotthuss Mechanism: Proton Currents in Nature and Biomimetic Devices
Marco Rolandi
Materials Science and Engineering
University of Washington, Seattle USA
Proton transport in nature is important for ATP oxidative phosphorylation, the HCVN1
voltage gated proton channel, light activated proton pumping in bacteriorhodopsin, and the
proton conducting single water file of the antibiotic gramicidin. In these systems, protons
move along hydrogen bond networks formed by water and the hydrated biomolecules (proton
wires). Along these wires, protons hop according to the Grotthuss mechanism. Here, I will
discuss proton transport along proton wires in membrane proteins and how we mimic these
wires with biopolymers. I will introduce complementary H+- and OH
-- FETs with PdHx proton
conducting contacts and novel device architectures with memristive behaviour.
Thursday, 08:30 – 09:30
40
The Neuron Bridge: a Novel Platform Architecture
for Directed Nerve Regeneration
Stephen B. Bandini,a Shivani Singh,
b Patrick E. Donnelly,
a
Jean E. Schwarzbauer,b
Jeffrey Schwartza
a Department of Chemistry, Princeton University, Princeton, NJ 08540
bDepartment of Molecular Biology, Princeton University, Princeton, NJ 08540
Central and peripheral nerve injury results in immediate inflammation and scar tissue
formation that obstructs natural and surgical healing.1,2
To regenerate a severed neural
connection, an ideal scaffold would serve as a bridge that guides neural cell navigation around
the injury site; if a prosthetic device is required to restore function, this bridge would direct
axons to the correct electrode connections.3 Clinically approved conduits for nerve guidance
may be limited by inadequate waste exchange and diffusion of nutrients, compress the
regenerating nerve, and lack sufficient extracellular matrix (ECM) to guide neurons.4 Indeed,
a crucial step in natural nerve repair involves formation of an ECM bridge to guide the
Schwann cells that support incoming neural cells.5 With the goal of recapitulating a native-
like, spatially aligned ECM to serve as a neuron bridge that is dimensionally scalable and
open to diffusion of nutrients and waste exchange, we have developed a method to fabricate
patterned, nanoscale interfaces on biomedical polymer surfaces that do not alter the elastic
modulus of the polymers.6 The patterned interface spatially directs fibroblast cell adhesion
and spreading, and because it is nanometers thin, allows to grow to confluence and assemble
ECM that is aligned with the underlying pattern. To demonstrate the utility of cell-assembled
ECM as a neuron bridge, neural analog PC12 cells plated on decellularized matrix align in the
direction of the interface pattern. Because the nano-architecture of the patterned, cell-adhesive
interface includes a high dielectric material, potential applications of the interface functioning
as a capacitance-based neural stimulation device will also be addressed.
SEM image (left) of interface pattern on biomedical polymer PET. Fibroblast cells assemble
aligned fibronectin ECM (green) when grown on the surface, and ECM serves as a platform
for PC12 cell alignment (red). Scale bars = 100 µm, both images; arrows indicate pattern
direction.
1. Silver, J., Miller, H. Regeneration beyond the glial scar. Nat. Rev.Neurosci. 5, 146-156 (2004).
2. Burnett, M.G., Zager, E.L. Pathophysiology of peripheral nerve injury: a brief review. Neurosurg Focus. 16, 1-7
(2004).
3. Wutten, W.L.C. Selective electrical interfaces with the nervous system. Annu. Rev. Biomed. Eng. 4, 407-453
(2002).
4. Daly, W., Yao, L., Zeugolis, D., Windebank, A., Pandit, A. A biomaterials approach to peripheral nerve
regeneration: bridging the peripheral nerve gap and enhancing functional recovery. J. R. Soc. Interface. 9, 202-
221 (2012).
5. Deumens, R., Bozkurt, A., Meek, M., Marcus, M.A.E., Joosten, E.A.J., Weis, J., Brook, G.A. Repairng injured
peripheral nerves: Bridging the gap. Prog Neurobiol. 92, 245-276 (2010).
6. Donnelly, P.E., Jones, C.M., Bandini, S.B., Singh, S., Schwartz, J., Schwarzbauer, J.E. A simple nanoscale
interface directs alignment of a confluent cell layer on oxide and polymer surfaces. J. Mater. Chem. B. 1, 3553-
3561 (2013).
Thursday, 09:30 – 09:45
41
Methods for Biofunctionalization of Cellulosic Surfaces
for Biosensing Applications
Stefan Köstler,a Tamilselvan Mohanselvan,
b,c Stefan Spirk,
b,d Stefan Höllbacher,
a,b
Rupert Kargl,b,c
Karin Stana-Kleinschek,c Volker Ribitsch
b
a JOANNEUM RESEARCH - Institute for Surface Technologies and Photonics, Franz-Pichler
Straße 30, A-8160 Weiz, Austria b Institute of Chemistry, University Graz, Heinrichstraße 28, 8010 Graz, Austria
c Institute for Engineering and Design of Materials, University of Maribor, Slovenia
d Institute for Chemistry and Technology of Materials, Graz University of Technology, Graz
Austria
Cellulose is the most abundant biopolymer on earth, being a major part of the cell walls of
plants. It displays remarkable mechanical properties and is stable in a wide range of
environmental conditions. Therefore it has found widespread applications ranging from
fiber and membrane technology, to packaging films. More recently, cellulose was also
used for (organic) electronic devices.1 Furthermore, cellulose and many of its derivatives
show excellent biocompatibility and interaction with other biomolecules in a large number
of biotechnological and life science applications. Therefore cellulose derivatives are well
suited for the construction of biosensor and bioanalytical devices, requiring the
immobilization of specific receptors and capture molecules (oligonucleotides, proteins,
antibodies, etc.) in a controlled and spatially patterned manner. Cellulosic materials are
ideal matrices for such patterned biofunctionalization. Cellulose can be deposited and
patterned as thin films on a variety of substrates.2 Furthermore, anionic as well as cationic
cellulose derivatives can be used for further functionalization of such surfaces and allow
for efficient binding of biomolecular receptors such as DNA strands, proteins or
antibodies.2,3
Efficient biofunctionalization methods will be crucial for successful
development of bioelectronics based sensors and analytical devices.
a) b)
(a) DNA detection on patterned cellulose coatings on polymer surface,2 and (b)
adsorption of proteins to cationic cellulose derivative.3
1. Petriz A, Wolfberger A., Fian A., Irimia-Vladu M., Haase A., Gold H., Rothländer T., Griesser T.,
Stadlober B., Cellulose as biodegradable high-k dielectric layer in organic complementary inverters. Appl.
Phys. Lett. 103, 153303 (2013).
2. Kargl R., Mohan T., Köstler S., Spirk S., Doliška A., Stana-Kleinschek K, Ribitsch V., Functional
patterning of biopolymer thin films using enzymes and lithographic methods. Adv. Funct. Mater. 23 308–
315 (2013).
Mohan T., Ristic T., Kargl R., Doliška A., Köstler S., Ribitsch V., Marn J., Spirk S., Stana-Kleinschek K.,
Cationically rendered biopolymer surfaces for high affinity support matrices. Chem. Commun. 49, 11530-
11532 (2013).
Thursday, 09:45 – 10:00
42
Ionic Circuits and Devices Combining Electronic, Microfluidic and Biomimetic
Structures
Orlin D. Velev
Department of Chemical and Biomolecular Engineering, North Carolina State University,
Raleigh, NC 27695
[email protected] http://crystal.che.ncsu.edu/
We will present strategies for the fabrication of electrically functional circuits and devices
operating on ionic currents through gels in water environment. These devices combine
elements of electrochemistry, electronics, and microfluidics. Their potential applications are
inspired by essential biological processes such as neural transmission. Microfluidic channels
and networks in such ionic devices play the role of wires and circuits in conventional
electronics. Earlier, we reported a new class of gel diodes with rectifying junction formed by
interfacing water-based gels doped with polyelectrolytes of opposite charge and operating on
the basis of conductance of the counterionic layers around the polyelectrolyte molecular
backbone [1]. The rectification ratio of such diodes can be as high as 4x104 when hydrated
SiO2 nanolayers serve as one of the diode components [2]. The wiring of hydrogel diodes
through microchannels filled with liquid metal, an eutectic Ga-In (EGaIn) alloy, made
possible the construction of diode and memristor arrays [3,4]. The memristor circuits use the
intrinsic bistability of the hydrogel/EGaIn interface. They are made completely from soft and
quasi-liquid material and can store a few bits of electrically writeable and readable
information. We will also demonstrate how water-based gels doped with polyelectrolytes can
be used as the core of novel photovoltaic cells [5]. We will discuss how such devices can form
the basis of bioinspired “artificial leaves” by embedding a microvascular network of channels
mimicking leaf venation inside the gel. The concept was demonstrated in a preliminary way
by constructing self-regenerating water-based dye sensitized solar cells [6]. The results point
the way for constructing truly biomimetic energy harvesting systems. They can also find
applications in novel hydrogel actuators and elemnts for “soft robotics” [7].
1. O. J. Cayre, S.-T. Chang and O. D. Velev, J. Am. Chem. Soc. 129, 10801 (2007).
2. H.-J. Koo, S.-T. Chang and O. D. Velev, Small, 6, 1393 (2010).
3. H.-J. Koo, J.-H. So, M. D. Dickey and O. D. Velev, Adv. Funct. Mater. 22, 625 (2012).
4. H.-J. Koo, J.-H. So, M. D. Dickey and O. D. Velev, Adv. Mater, 23, 3559 (2011).
5. H.-J. Koo, S. T. Chang, J. M. Slocik, R. R. Naik and O. D. Velev J. Mater. Chem., 21, 72 (2011).
6. H.-J. Koo and O. D. Velev, Sci. Rep. (Nature), 3, 2357, 1-6 (2013).
7. E. Palleau, D. Morales, M. D. Dickey and O. D. Velev, Nature Comm., 4, 2257, 1-7 (2013).
Thursday, 10:30 – 11:30
43
Organic semiconductor/insulator blends: enabling ions flow for bioelectronics
applications
Celia M Pacheco-Moreno,1,2
Damia Mawad,2,3
Jonathan Rivnay, 4 George Malliaras,
4 Molly
M Stevens, 1,2,3,5
Natalie Stingelin 1,2
1 Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, UK
2 Department of Materials, Imperial College London, London SW7 2AZ, UK.
3 Department of Bioengineering, Imperial College London, London SW7 2AZ, UK.
4 Department of Biolelectronics, École Nationale Supérieure des Mines, CMP-EMSE, MOC,
880 route de Mimet, 13541 Gardanne - France
5 Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, UK
In recent years, the bioelectronics field has seen the use of an increasing variety of conducting
polymers because they promise to display tunable mechanical properties (flexibility) and the
ability to form an intimate interface with living tissue – in strong contrast to their inorganic
counterparts.1 Even though transduction of ionic biosignals into electronic signals is thought
to be the key mechanism for successful integration of electronic devices in biological systems,
little insight has so far been gained that allows understanding the interplay of electronic and
ionic conductivity in the currently employed materials.2 Here we present a straight-forward
and chemically inert materials science approach to this challenge that promises to control
mixed ionic/electronic transport in ‘plastics’ by blending organic semiconductors with
insulating polymers. This assists in inducing a more polar nature to the resulting systems and
introduces the capability of controlling the interdiffusion of biological media through the final
structures. We will demonstrate that electronic transport can be maintained in such
multicomponent systems upon blending with the insulating matrix. Moreover, initial studies
show faster switching response in large-scale organic electrochemical transistors (OECT)
when using blend systems compared to devices fabricated with a single-component
conducting layer. This observation suggests that our blend system shows efficient ionic
conductivity. We tentatively relate this desirable behavior of the semiconductor:insulator
blends to the more polar nature of the latter active layers, introduced through the insulating
(commodity) polymers, in addition to the swelling of the blend in the aqueous electrolyte. We
thus show that the use of conducting/insulating polymer blends has the potential to bring
multifunctionality to the final material systems, including biological activity, biodegradation,
topological cues, etc., which in turn promises to enable more specific interactions with
biological systems.
1. Owens, R. M. & Malliaras, G. G. Organic Electronics at the Interface with Biology. MRS Bulletin. 35, 449–
456 (2010).
2. Ghosh, S. & Inganäs, O. Networks of Electron-Conducting Polymer in Matrices of Ion-Conducting Polymers.
Applications to Fast Electrodes. Electrochemical and Solid-State Letters. 3 (5), 213–215 (2000).
Thursday, 11:30 – 11:45
44
Electrolyte-gated Organic Field-Effect Transistors for Ion Sensing Applications
K. Schmoltner,a J. Kofler,
a A. Klug,
a E. J. W. List,
a,b
a NanoTecCenter Weiz Forschungsgesellschaft mbH, Franz-Pichler-Strasse 32, 8160 Weiz,
Austria; b Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz,
Austria;
For the emerging fields of biomedical diagnostics and environmental monitoring, where
sensor platforms for in-situ sensing of ions and biological substances in appropriate
aqueous media are required, electrolyte-gated organic field-effect transistors (EGOFETs)
seem to be the transducers of choice. Due to the formation of an electric double layer at
the electrolyte/organic semiconductor interface, they exhibit a very high capacitance
allowing for low-voltage and water-stable operation. In combination with the outstanding
properties of organic devices like biocompatibility, low-temperature processability on
flexible substrates, as well as the possibility to tune the physical and chemical properties
enhancing the selectivity and sensitivity, EGOFET-based sensors are a highly promising
novel sensor technology.
Here the realization of the first ion-selective EGOFETs is discussed. In this context the
device characteristics of poly(3-hexylthiophene) (P3HT) – based EGOFETs for various
substrates using water with different concentrations of NaCl as an electrolyte and various
gate electrode materials, are presented. In order to obtain a sensitive as well as selective
response to sodium a commercial available ion selective membrane was introduced. This
novel potentiometric sensor showed a sensitive linear response for a broad detection range
between 10-6
M and 10-1
M Na+ and a selective as well as reversible response without a
complex recovering process was achieved.1
Cross section of an ion-sensitive EGOFET (left); Source-drain current response to
increasing Na+ concentration of a typical ion-sensitive EGOFET with a PVC ion-selective
membrane (inset: ISEGOFET with flowcell and reference electrode ) (right).
1. Schmoltner, K., Kofler, J., Klug, A. & List-Kratochvil, E. J. W. Electrolyte-gated field effect transistor
for selective and reversible ion detection. Adv. Mater. 25 (47), 6895–6899 (2013).
Thursday, 11:45 – 12:00
45
Charge dynamics in biomolecules
G. Gruner
Department of Physics
University of California Los Angeles
The motion of electric charges: charge transfer, charge transport, and maybe even a finite electrical
conductivity has also important consequences for biology.
In this second lecture I will focus on issues related to motion of electrical charges in biomolecules. The
following topics will be covered (1) Fundamentals of charge transfer, charge transport, dc and ac
electrical conductivity in one dimensional (1D) systems, (2) models that describe charge propagation
in one dimension for static and for a dynamic, fluctuating environment, such as provided by bio-
molecules in vitro and (3) the response of DNA to applied electric fields as examined by contactless ac
measurements under different buffer conditions.
0.01 0.1 1 10 100 1000
1E-3
0.01
0.1
1
10
100
10001E-4 1E-3 0.01 0.1 1
DNA UV data
DNA 5% R.H.
DNA 95% R.H.
Wittlin et. al.
s1 (W
cm
)-1
Frequency (THz)
Photon Energy (eV)
Friday, 08:30 – 09:30
46
Anti-microbial conductive biocomposites based on nanofibrillated cellulose,
polypyrrole and Ag-nanoparticles Rose-Marie Latonen,
a Patrycja Bober,
b Jun Liu,
c Chunlin Xu,
c Kirsi, Mikkonen,
d Atte Von
Wright e
a Process Chemistry Centre, Laboratory of Analytical Chemistry, Åbo Akademi University,
Biskopsgatan 8, FIN-20500 Åbo, Finland b Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic,
162 06 Prague 6, Czech Republic c Process Chemistry Centre, Laboratory of Wood and Paper Chemistry, Åbo Akademi
University, Porthansgatan 3, FIN-20500, Åbo, Finland d Department of Food and Environmental Sciences, University of Helsinki, Latokartanonkaari
11, FIN-00119, Helsinki, Finland e Department of Biosciences, University of Eastern Finland, P.O. Box 1627, FIN-70211,
Kuopio, Finland
Nanofibrillated cellulose (NFC), originated from wood fibers, prepared by 2,2,6,6-
tetramethylpiperidine-1-oxyl radical (TEMPO) mediated oxidation resulting in a fiber size of
5 nm in width and hundreds of nanometers in length has shown high strength, stiffness and
good film forming properties.1 By using NFC as template for polypyrrole (PPy) and Ag-
nanoparticles, biocompatible, electroconductive and anti-microbial free-standing composite
films (PPy/Ag/NFC) could be prepared. Pyrrole (Py) was chemically oxidized with Fe(NO3)3
or AgNO3 or their mixtures in 0.5 w-% aqueous NFC solutions. The concentration of Py was
0.005 M and the oxidant-to-Py mole ratio was fixed to 2.5. The morphology of the
PPy/Ag/NFC composite films and the particle size of Ag in the films were studied by
Scanning Electron Microscopy. The amount of Ag-deposits in the composites was estimated
by Thermal Gravimetric Analysis. The structure of the PPy/Ag/NFC films was characterized
by FTIR and Raman spectroscopy and the electroactivity of the composites was confirmed by
cyclic voltammetry. The electrical conductivity was found to be approximately 10-3
S cm-1
measured by the 4-point probe method. The studied PPy/Ag/NFC composite films showed
also good mechanical properties (tensile strength, elongation at break, Young’s modulus) and
rather low oxygen permeability. Finally, the anti-microbial properties of the PPy/Ag/NFC
composite films with different Ag-nanoparticle contents were studied towards the human skin
bacteria Staphylococcus Aureus.
SEM images of a) PPy/NFC, b) PPy/Ag(20%)/NFC and c) PPy/Ag(80%)/NFC
Klemm, D., Kramer, F., Moritz, S., Lindström, T., Ankerfors, M., Gray, D. & Dorris, A. Nanocelluloses: A
new family of nature-based materials. Angew. Chem. Int. Ed. 50, 5438–5466 (2011).
a) b) c) 200 m 200 m 200 m
Friday, 09:30 – 09:45
47
Chemically modified mesoporous biosilica from
Thalassiosira weissflogii diatom for biological applications
Danilo Vona a, Stefania R. Cicco
b, Roberta Ragni
b, Elvira De Giglio
b, Monica Mattioli
Belmonte d,
Roberto Gristina c, Fabio Palumbo
c and Gianluca M. Farinola
b
d Università Politecnica delle Marche, Dipartimento di Scienze Cliniche e Molecolari, via
Tronto 10/a, 60020, Torrette di Ancona
c CNR IMIP, Via Amendola 122/d-o, Bari, Italy
b Università degli Studi di Bari “Aldo Moro”, via Orabona 4, Bari, Italy
a CNR ICCOM, via Orabona 4, Bari, Italy
Mesoporous silica materials are extensively exploited in a wide number of nanotechnological
applications including catalysis, separation and sensing. Micro- and nano-texturing is also
remarkably useful for biological applications. We focused on a biochemical way to obtain
biosilica from Thalassiosira weissflogii, a pelagic centric diatom from Oceans. Frustules,
specific and really polymorphic silica shells produced by diatoms, have in fact be used in
photonics, molecular separation and detection and biosensing1. Here we report a series of
frustules-based scaffold systems obtained by chemical modification of the outer surface of the
diatom shells with a specific anti-oxidant moiety (TEMPO radical trap) via the APTES-
method and the resulting material could be also used as biosilica sponge for drug
loading/delivery of ciprofloxacin (antibiotic). We also performed modifications of frustules
surfaces using chemistry of organosilanes to obtain specifically and covalently decorated
nanotextured shells to study cell biology of adhesion at preliminary stage.
This figure shows an example of chemical modification of frustule surface with a
pharmacological moiety (TEMPO moiety).
1. W. Yang, P. J. Lopez, G. Rosengarten, Analyst, 136, 42-53, 2011,.
Friday, 09:45 – 10:00
48
Organic Field Effect Transistors as Biosensors and Cell signal Transducers:
principles, fabrication, operations
Fabio Biscarini
Life Science Dept. - University of Modena and Reggio Emilia
Via Campi 183, I-41125 Modena, Italy
e-mail: [email protected]
web-page: http://personale.unimore.it/Rubrica/dettaglio/fbiscari
personal web-page: http://www.bo.ismn.cnr.it/biscarinilab/index.php/en/.
Friday, 10:30 – 11:30
49
Electrochemical reduction of immobilized dehydrogenase enzymes
for CO2 reduction
S. Schlager, D. Hiemetsberger, D. Apaydin, E. Portenkirchner, D. Voglhuber, N. S. Sariciftci
Linz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes
Kepler University Linz, Austria
Enzymatic reduction reactions are well known from biological systems.1 CO2 is reduced to
formate, formaldehyde or methanol by formate dehydrogenase, formaldehyde dehydrogenase
and alcohol dehydrogenase respectively with the aid of the coenzyme Nicotinamidadenin
dinucleotide (NADH). We present the immobilization2 of these enzymes in alginate based
matrices for a sustainable, reproducable CO2 reduction. Different alginate containing gels
were investigated for efficient CO2 conversion.3,4
Further modification of the gels with
PEDOT:PSS increases the conductivity of the material. This offers the opportunity for
electrochemical application of the enzyme containing systems and therefore to substitute
NADH as electron provider. Production of formate and methanol are shown for the enzymatic
CO2 reduction in electrochemical and non-electrochemical experiments. Products were
analysed in ion chromatography and gas chromatography. Conductivity of the PEDOT:PSS
modified alginate gel was determined by four probe measurement. Electrochemical
measurements were performed in a one compartment cell using alginate covered Pt as
working electrode. Cyclic voltammograms were recorded for electrochemical
characterisation. Results from CO2 saturated samples are compared to N2 purged setups to
proof product generation from CO2 reduction.
1. M. Aresta, A. Dibenedetto, Ref. Mol. Biotechnol., 90, 113-128(2002).
2. T. Reda, C. M. Plugge, N. J. Abram, J. Hirst, PNAS, 105, 10654-10658 (2008).
3. O. Heichal-Segal, S. Rapport, S. Braun, Nat. Biotechnol., 13, 798-800 (1995).
4. Y. Lu, Z.-Y. Jiang, S.-W. Xu, H. Wu, Catal. Today, 115, 263-268 (2006).
Friday, 11:30 – 11:45
50
Functionalization of PVDF membranes to control PVDF – PEDOT/PSS
interface strength for increased cycle life of artificial muscles
Simaite Aiva,a,b
Tondu Bertrand,a,b
Clergereaux Richard,c Descamps Emeline,
a Souères
Philippe,a Bergaud Christian
a
a LAAS-CNRS, Univ de Toulouse, 7 avenue du Colonel Roche, BP 54200, F-31031 Toulouse
cedex 4, France b INSA-Toulouse, 135 Avenue de Rangueil, 31400 Toulouse, France
c LAPLACE-CNRS, Université Paul Sabatier - Bat 3R3, 118 route de Narbonne 31062
Toulouse cedex 9, France
Ionic electroactive polymer (iEAP) based actuators, shortly called artificial muscles are
promising materials in the field of bio-mimetics and implantable devices. In artificial
muscles motion is generated by swelling and contraction of the material, due to transport
of ions and solvent from one electrode to another. Typical polymer based actuators are
made of two electrodes and an ion-storing membrane sandwiched to a trilayer (Figure 1a).
Due to high conductivity, mechanical properties and oxidative stability poly(3,4-
ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT/PSS) are often
used as an electrode and replace stiffer metal-polymer composites1. Nevertheless, due to
delamination of components, conducting polymer actuators suffer from short cycle life.
Cycle life is improved if hydrophobicity of the membrane is decreased since it strengthens
the interface between layers1. We suggest using argon plasma-induced chemical grafting
to modify poly(vinylidene fluoride) (PVDF) membrane’s surface in order to improve the
actuator’s performance2. Furthermore plasma discharge parameters or amount of grafting
precursor allow control of penetration of conducting polymer in the membrane, that could
lead to better understanding of actuation mechanisms.
Figure 1: a) EDX picture of PEDOT/PSS-PVDF-PEDOT/PSS (sulfur of PEDOT/PSS
shown in green) trilayer structure of the actuator; b) Merged photo of the actuator in the
initial position (blue), after applied +2Volts (yellow) and -2Volts (red ) .
1. Ikushima, K., John, S., Ono, A. & Nagamitsu, S. PEDOT/PSS bending actuators for autofocus
micro lens applications. Synthetic Metals 160, 1877–1883 (2010).
2. Chang, Y. et al. Hemocompatibility of Poly(vinylidene fluoride ) Membrane Grafted with
Network-Like and Brush-Like Antifouling Layer Controlled via plasma-induced Surface
PEGylation. Langmuir. 27, 5445–5455 (2011).
5mm
PEDOT/PSS
PEDOT/PSS
PVDF
Interfacial layer
Interfacial layer
Friday, 11:45 – 12:00
51
Poster Abstracts
Poster Session, Tuesday February 25th
, 19:00
(organized alphabetically by last name of presenting author)
52
Facilitating artificial glutamate-based stimulation of degenerated retina Oliya S. Abdullaeva, Manuela Schiek, Jürgen Parisi
Energy and Semiconductor Research Laboratory, Department of Physics, Carl von Ossietzky
University of Oldenburg, D-26111 Oldenburg, Germany
L-glutamate, the salt of the proteinogenic glutamic acid, plays a
major role in metabolic processes and is the main excitatory
neurotransmitter in the central nervous system of the brain.
Phototransduction, memory, and even learning processes depend
on L-glutamate.1
Phototransduction is a multi-step process that takes place in the
retina tissue of the eye. It consists of photoreceptor cells that
absorb photons. Upon absorption a signal cascade is triggered which results in the release of L-
glutamate. This transmission of electric signals by L-glutamate in to the brain is the key step in
the process of phototransduction. Gradual degeneration of photoreceptors leads to blindness as
observed in deceases like retinitis pigmentosa due to the lack of L-glutamate. Our aim is to create
an artificial device that would be capable of binding and consequently releasing L-glutamate.
These could then be implanted into the eyes and imitate the function of photoreceptor cells.2,3,4
Previous work has shown that organic conducting polymer films based on overoxidized
polypyrrol (PPy) can enantioselectively bind and release L-glutamate (Glu ions) using an applied
potential functioning as a molecular switch.5
An interesting approach in the future would be
the application of supramolecular systems. The
idea is to synthesize nanoporous materials or
supramolecular polymers that function as host
system and release L-glutamate when
photochemically modified. This would make
the use of electrochemically induced release of
L-glutamate redundant. Calixarene,
cyclodextrines or even Metallic-Organic-
Frameworks (MOF) could be potential host
molecules for the encapsulation of L-glutamate.
1. Ling, M., Ping, W., Guoxiang C., Chenxin C., Yongming S., Zhenhong Y. Low potential detection of
glutamate based on the electrocatalytic oxidation of NADH at thionine/single-walled carbon nanotubes
composite modified electrode. Biosensors and Bioelectronics 24, 1751-1756 (2009).
2. Kandel, E. R., Schwartz, J. H., Jessell, T. M., Siegelbaum, S. A., Hudspeth, A. J. Principles of Neural Science.
(McGraw-Hill, 2012).
3. Hartong, D. T., Berson, E. L., Dryja, T. P. Retinitis pigmentosa. Lancet 368, 1795-1809 (2006).
4. Farrar, G. J., Kenna, P. F., Humphries, P. On the genetics of retinitis pigmentosa and on mutation-independent
approaches to therapeutic intervention. EMBO J. 21, 857-864 (2002).
5. Meteleva-Fischer, Y. V., Von Hauff, E., Parisi, J. Electrochemical Synthesis of Polypyrrole
P1
53
Amyloid Fibrils as Dispersing Agents for Oligothiophenes: Control of
Photophysical Properties through Nano Scale Templating and Flow Induced
Fibril Alignment Fredrik BäcklundA, Fredrik WesterlundB, Olle InganäsA and Niclas SolinA
ADepartment of Physics, Biology and Chemistry, Linköping University, Linköping, Sweden BDepartment of Chemical & Biological Engineering, Chalmers University of Technology, Gothenburg,
Sweden
Nanowires formed from aggregated proteins, so called amyloid fibrils, can serve as an
excellent dispersing agent for hydrophobic oligothiophenes, such as α-sexithiophene (6T).
By solid state mixing of 6T with a protein capable of self-assembly a composite material
is formed that after dissolution undergoes self-assembly. In this manner we can prepare
6T-containing protein fibrils with typical diameter of 5-10 nm and lengths in the
micrometer range. Furthermore, the protein fibrils are capable of orienting 6T along the
fibril long axis. The resulting aqueous fibril dispersions are a readily available source of
oligothiophenes that can be processed from aqueous solvent, and we demonstrate the
hierarchical assembly of fibrils into macroscopic structures exhibiting polarized emission.
54
Proton Transport in Hydrogen-Bonded Molecular Solids
E. Meltem Akcay Ballieker, Eric Daniel Głowacki, Cigdem Yumusak, Halime Coskun,
N.Serdar Sariciftci
a Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler
University of Linz, A-4040 Linz, Austria
Biologically-inspired electronic devices have been gaining interest for possible application at
the interface with living tissue. Though modern electronics utilize transport of electrons,
biochemical systems rely exclusively on ionic and protonic currents because these systems
mostly consist of water which has poor electron but high ion/proton conductivity. Thus
protonics, based on proton (hydrogen ion) conduction1,2
, is an emerging research area.
Hydrogen ions hop through hydrogen-bond network of material just as described by Gratthuss
transport mechanism. In this report, we used indigo and similar pigment quinacridone as
proton active biocompatible hydrogen bonded3 materials. At first, we demonstrate humidity
response of glucose in a MIM structure. We use hydrated glucose4 as a protonic conductor to
allow selective injection/extraction of protons and blocking of electronic transport in the
hydrogen-bonded pigments.
1. Zhong, C., Deng, Y., Roudsari, A.F., Kapetanovic, A., Anantram, M.P., Rolandi, M. Nature and
Constitution of Shellac. Nature Communications. 2, (2011). 2. Deng, Y., Josberger, E., Jin, J., Rousdari, A.F., Helms, B.A., Zhong, C., Anantram, M.P., Rolandi, M.
Science Reports 3, 2013
3. Glowacki, D.E., Irimia-Vladu, M., Bauer, S., Sariciftci, N.S. J. Matter Chem. B, 1, 3742-3753 (2013).
4. Irimia-Vladu, M., Troshin, A.P., Reisinger, M., Schwabegger, G., Ullah, M., Schwoediauer, R.,
Mumyatov, A., Bodea, M., Fergus, W.J., Razumov, V.F., Sitter H., Bauer, S., Sariciftci, N.S. Organic
Electronics 11 1974-1990,(2010).
P2
55
Biocatalyst composite coatings on titanium based materials improve cell growth
and proliferation of human cells
Felicia Antohea, Luminita Ivan
a, Oana Rasoga
b, Carmen Bratu
b, Irina Zgura
a, Marimona
Miroiuc, Nicolaie Stefan
c, Valentina Grumezescu
c, Cristina Nita
c, Gianina Popescu Pelin
c,,
Anita Visanc and Gabriel Socol
c
a Institute of Cellular Biology and Pathology N. Simionescu, Bucharest, Romania
b National Institute of Materials Physics, Magurele, Ilfov, Romania
c National Institute for Lasers, Plasma and Radiation Physics, Magurele, Ilfov, Romania
Aim: Huge amount of money are spend every year for the treatment of skeletal disorders
including the bone loss or damages during traumatic events. The study focused on the
identification and optimization of the different biopolymers deposition on titanium based
materials carrying bioactive molecules that are anabolic for bone, improving cell growth and
proliferation for rapid musculoskeletal recovery therapies.
Materials and methods: Different polymers alone or in mixtures were investigated in form of
thin films for their degradation and solubility properties. Selected bio-composites were
deposited as thin films on titanium plates using two techniques: Dip-Coating (DC) and Matrix
Assisted Pulsed Laser Evaporation (MAPLE). The coatings were optimized by examination
under Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy
(FTIR), X Ray Diffraction (XRD) and wettability tests. A versatile device was designed to
measure the degradation or solubility of polymeric matrix as well as the release of the
bioactive macromolecules under dynamic flow of simulated body fluid (SBF). The impact on
the cells culture of the bioactive macromolecules incorporated into the polymeric matrix was
evaluated in vitro. Two types of cell lines, human osteosarcoma cells (SaOs2) and vascular
endothelial cells EA hy 926 (Edgel et al., 1983) were used to search for the coatings
biocompatibility and effects on growth and proliferation of the cells.
Results: The collected data allowed the selection of optimized polymer composites and the
deposition parameters to obtain functionalized coatings onto the titanium plates. Bioactive
macromolecules as lysozyme, fibroin, fibronectin, etc. were successfully incorporated in the
deposited polymers and the release kinetics of each incorporated proteins was determined as a
function of the polymer and physical characteristics of the composite layer. The
biocompatibility of the functionalized titanium plates showed that both cell lines tested exhibit
a high rate of viability (up to 97%) on selected structures that will be further tested in in vivo
animal model.
The work was supported by project PN-II-PCCA No. 153/2012 from CNCSIS-UEFISCSU
and grants from Romanian Academy.
P3
56
Temperature-dependent spectroscopic ellipsometry of nature-inspired
conjugated semiconducting materials
Lukas Bernhauser,a Eric Daniel Głowacki,
a Christoph Cobet
b, Markus Scharber
a, Kurt
Hingerl b, Niyazi Serdar Sariciftci
a
a Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University of Linz, A-4040
Linz, Austria
b Zentrum für Oberflächen- und Nanoanalytik , Johannes Kepler University of Linz, A-4040
Linz, Austria
Spectroscopic Ellipsometry is a useful technique for determining the dielectric properties of
organic semiconductors.
Herein we describe our studies of organic semiconducting thin films, using the
semiconducting polymer poly(3-hexylthiophene) (P3HT) as a standard. We focused our
investigations as well on nature-inspired high dielectric-constant hydrogen-bonded pigments
such as indigoids to determine the complex dielectric functions of these materials.
As a special method to study important temperature transitions in organic semiconductors, we
report an in situ technique for measuring optical properties as a function of temperature and
also show that this method may be used to monitor chemical reactions occurring in thin
organic films, including thermal cleavage of protection groups used for solution-processing
hydrogen-bonded thin films. We also explain the challenges and limitations one is confronted
with when measuring optical properties using such methods
Figure 1: Refractive Index of Epindolidione
1. Glowacki E.D. et al. A facile protection - deprotection route for obtaining indigo
pigments as thin films and their applications in organic bulk heterojunctions.
ChemComm., 49, 6063 (2013).
P4
57
Nanofibers from Naphthyl End-Capped Oligothiophenes: The Influence of
Methoxy Functionalization
Frank Balzer,a Manuela Schiek,
b Andreas Osadnik,
c Ivonne Wallmann,
c Jürgen Parisi,
b Horst-
Günter Rubahn,a Arne Lützen
c
a MCI, University of Southern Denmark, Alsion 2, Dk-6400 Sønderborg, Denmark
b Institute of Physics, Energy and Semiconductor Research Laboratory, University of
Oldenburg, D-26111 Oldenburg, Germany
c Kekulé-Institute for Organic Chemistry and Biochemistry, University of Bonn, Gerhard-
Domagk-Str. 1, D-53121 Bonn, Germany
It has been shown in the past that methoxy functionalization of para-quaterphenylene
substantially improves the formation of aligned nanofibers.1 Here the influence of
methoxy functionalization on the growth of another class of small, semiconducting
organic molecules is investigated, i.e. on the formation of nanoaggregates from naphthyl
end-capped oligothiophenes, Fig. 1(a). Extended focus laser scanning microscope images
of NaT and MONaT in Figs. 1(b) and (c), respectively, show the improved crystallization
into aligned fibers due to functionalization. Polarized fluorescence microscopy2 reveals
spatially resolved molecular orientations as well as molecule orientations within the
aggregates.
In air Ostwald ripening of the entities is observed. The morphological variations of the
aggregates result in specific optical signatures, disclosed by temperature dependent and
spatially resolved fluorescence spectra.3
1. Schiek, M., Lützen, A., Al-Shamery, K., Balzer, F., Rubahn, H.-G. Nanofibers from Methoxy
Functionalized para-Phenylene Molecules Surf. Sci. 600, 4030–4033 (2006). 2. Balzer, F., Henrichsen, H., Klarskov, M., Booth, T., Sun, R., Parisi, J., Schiek, M., Bøggild, P. Directed
self-assembled crystalline oligomer domains on graphene and graphite Nanotechnology 25, 035602
(2014).
3. Balzer, F., Schiek, M., Osadnik, A., Wallmann, I., Parisi, J., Rubahn, H.-G., Lützen, A.
Substrate Steered Crystallization of Naphthyl End-Capped Oligothiophenes into Nanowires:
The Influence of Methoxy-Functionalization Phys. Chem. Chem. Phys (2014), in press.
RS
R
R S
S R
RS
S
SR
1 NaT (R = H), 4 MONaT (R = MeO)
2 NaT2 (R = H), 5 MONaT2 (R = MeO)
4 NaT3 (R = H), 6 MONaT3 (R = MeO)
(a) (b) (c)
Figure 1: (a) 1-3 Naphthyl end-capped oligothiophenes and, 4-6 their methoxy
functionalized variants. Extended focus laser scanning microscope images of NaT (b) and
MONaT (c) deposited on muscovite demonstrate the influence of methoxy
functionalization on fiber growth. Olympus Germany is thanked for providing a LEXT
OLS4100 microscope.
P5
58
Extended π-system indigos – derivatizing a natural material for organic
electronics
Zeynep Bozkurt, Eric Daniel Głowacki, Dogukan Apaydin, Marzena Grucela-Zając, Gundula
Voss, Elisa Tordin, Niyazi Serdar Sariciftci
Linz Institute for Organic Solar Cells (LIOS)
Johannes Kepler University, Linz, Austria
Indigo and its derivatives are dyes and pigments with a long and distinguished history in
organic chemistry. Recently, applications of this ‘old’ molecule as a functional organic
building block for organic electronics applications have renewed interest in these molecules
and their remarkable chemical and physical properties.
Our recent research has focused on solution-based chemistry on the normally insoluble
indigo, through the use of thermally-cleavable protection groups. Chemistry based on this
protect-deprotect route enables enormous possibilities for the derivitization of indigo
molecules. Using soluble protected dibromoindigos, we have succeeded in applying C-C
coupling reactions such as Sonagashira and Suzuki couplings, allowing the attachment of π-
conjugated units to the indigo core. Herein we discuss our recent progress on derivatizing the
indigo molecule for enhanced performance in organic electronics applications.
1. Irimia-Vladu, M.; Głowacki, E. D.; Troshin, P. A.; Schwabegger, G.; Leonat, L.; Susarova, D. K.;
Krystal, O.; Ullah, M.; Kanbur, Y.; Bodea, M. A.; Razumov, V. F.; Sitter, H.; Bauer, S.; Sariciftci, N. S.
Adv. Mater. 2012, 24, 375–380.
2. Głowacki, E. D.; Leonat, L.; Voss, G.; Bodea, M.-A.; Bozkurt, Z.; Ramil, A. M.; Irimia-Vladu, M.;
Bauer, S.; Sariciftci, N. S. AIP Advances 2011, 1, 042132–042137.
3. Głowacki, E. D.; Irimia-Vladu, M.; Kaltenbrunner, M.; Gąsiorowski, J.; White, M. S.; Monkowius, U.;
Romanazzi, G.; Suranna, G. P.; Mastrorilli, P.; Sekitani, T.; Bauer, S.; Someya, T.; Torsi, L.; Sariciftci,
N. S. Adv. Mater. 2013, 25, 1563–1569.
4. Głowacki, E.D.; Voss, G.; and Sariciftci, N.S. Adv. Mater., 2013, 25, 6783–6800.
P6
59
Water-stable organic transistors based on H-bonded organic semiconductors
towards surface-modified transistor biodetectors
Halime Coskun, Eric Daniel Głowacki, Cigdem Yumusak , E. Meltem Akcay Ballieker,
N.Serdar Sariciftci
a Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler
University of Linz, A-4040 Linz, Austria
Biodetectors gain interest in the fields of medicine due to the translation of an analyte binding
event to an electrical signal. The motivation for applying organic field-effect devices to
biological sensing is their compatibility with flexible and large area substrates, and the
properties of organic materials being highly tunable for chemical sensitivity and therefore
being easily modified with receptor sites for specific interactions [1]. We investigate two
organic semiconductors, Epindolidione and Quinacridone, the H- bonded analogs of tetracene
and pentacene [2]. These materials have free -NH groups that can be readily modified with
various biomolecules via surface chemistry. Organic thin film transistors out of Epindolidione
and Quinacridone were fabricated and operated under water. The OFETs demonstrate
impressive stability in both ambient air and during operation in an aqueous environment. The
effect of H3O+ doping was seen in the increase of the OFF current during measurement under
water. Surface modification of the organic semicondurtors were conducted by condensation of
free –NH groups with Succinimidyl-Biotinate. Such modified devices demonstrate sensitivity
for Streptavidin in solution.
[1] Mark E. Roberts, Stefan C.B. Mannsfeld, Nuria Queralto, Colin Reese, Jason Locklin, Wolfgang Knoll,
Zhenan Bao, Water-stable organic transistors and their application in chemical and biological sensors, PNAS,
vol. 105, 2008, 12134- 12139
[2] Eric Daniel Głowacki, Mihai Irimia-Vladu , Martin Kaltenbrunner , Jacek Gasiorowski ,Matthew S. White ,
Uwe Monkowius , Giuseppe Romanazzi , Gian Paolo Suranna ,Piero Mastrorilli , Tsuyoshi Sekitani , Siegfried
Bauer , Takao Someya , Luisa Torsi, and Niyazi Serdar Sariciftci, Hydrogen- Bonded Semiconducting Pigments
for Air- Stable Field- Effect Transistors, Adv. Mater,2013, 2S, 1563-1569
P7
60
Influence of X-rays to electric features of organic-inorganic layers sensitized by
PbO and PbI2
Rokas Dobužinskas, Kęstutis Arlauskas, Andrius Poškus, Justas Varpučianskis
Department of Solid State Electrinics, Vilnius University, Saulėtekio al. 9, Vilnius, Lithuania
Organic semiconductors have recently been used as the transduction material in x-ray
detectors [1]. However, these devices have quite low sensitivity because of low
attenuation coefficient of thin organic layer [2]. We attempted to increase x-ray
attenuation by introducing dense high atomic number (Z) particles into organic hole
transport material [3].
Various types of branched carbazole and diphenylamine group organic materials on
Indium Tin Oxide (ITO) anode substrates have been prepared by casting with following
vacuum evaporation of Aluminum electrode on top of the layer. The influence of molar
mass and different chemical formula of the organic materials to electrical characteristics
have been examined. By investigating various organic material layers it have been
evaluated that the organic material with phenyl groups demonstrated the highest
photosensitivity to x-rays.
Fig 1. Dependencies of measured photocurrent of organic material V-169, V-169+PbO
and V-169+PbI2 hybrid layers on photon flux density per second to active area of sample
at 100 V on sample electrodes (+ITO)
The organic material layers with high atomic number nanoparticles of PbO and PbI2 have
been formed with a purpose to compare and examine photocurrent sensitivities to x-ray
radiation. The layers, using mixtures of phenyl group material (V-169) with powders of
PbO and PbI2 demonstrated linear dependencies on photon flux (Fig 1). These results
demonstrate possible potential of organic material compounds with high atomic
nanoparticles for application as x-ray sensors.
1. Agostinelli, T. A polymer/fullerene based photodetector with extremely low dark current for x-ray
medical imaging applications (Appl. Phys. Lett. 93 2008)
2. Poškus, A. Physics of the atom and experimental methods of nuclear physics (Vilnius University 2008)
3. Intaniwet, A. Heavy metallic oxide nanoparticles for enhanced sensitivity in semiconducting polymer
x-ray detectors (Nanotechnology 23 2012).
106
107
108
10-2
10-1
100
101
[photons/(s · cm2)]
I X-r
ay [
nA
]
V169
V169+PbO
V169+PbI2
I ~ 1
P8
61
High Performance Indium Tin Oxide-Free Solution Processed Organic
Photovoltaics
Efthymios Georgiou a, Marios Neophytou a and Stelios A. Choulis a
a Cyprus University of Technology, Molecular Electronics and Photonics Research Unit, 45
Kitiou Kyprianou St., 3041, Limassol, Cyprus
Nowadays, the need for inexpensive and green energy is vital due to the elimination of
conventional energy sources. Organic Photovoltaics (OPVs) have attracted intensive research
interest due to the ease of manufacturing with printing techniques. Indium tin oxide (ITO) is
widely used as a transparent electrode for OPV applications due to its conductivity and light
transmittance.1 The need of inexpensive, alternative to indium doped tin oxide (ITO)
transparent electrodes is imminent for cost-efficient OPVs. ITO-free transparent electrodes
can rely on inkjet-printed Silver (Ag) nanoparticles (NP) grids embedded into PEDOT:PSS
buffer layers.2 We present an in-depth investigation of the morphological evolution of the
inkjet printed Ag nanopartricle sintering process. The latter was combined with an ultimate
control of the printed grid design requirements for efficient ITO-free OPVs. We report on
glass/ITO-free P3HT:PC60BM and Si-PCPDTBT:PC70BM based OPVs with power
conversion efficiency of 2.8 % and 4.9% respectively.3 These devices exhibited minimal
losses when compared to reference ITO-based OPVs (figure 1).4
Figure 1: Illuminated (100mW/cm
2, A.M. 1.5G) J/V characteristics for Si-PCPDTBT:PC70BM
based devices. Ag NP/ PEDOT:PSS (red line) transparent electrode was employed and
compared with reference devices with ITO/ PEDOT:PSS (black line). Inset: the chemical
structure of the used materials and table with both device parameters.
1. Emmott, C., J., M., Urbina, A., Nelson, J., "Environmental and economic assessment of ITO-free
electrodes for organic solar cells", Sol. Energy Mater. Sol. Cells 97 14–21.(2012)
2. Neophytou, M., Hermerschmidt, F., Savva, A., Georgiou, E. & Choulis, S.A., "Highly efficient indium
tin oxide-free organic photovoltaics using inkjet-printed silver nanoparticle current collecting grids",
Applied Physics Letters, vol. 101, no. 19.(2012)
3. Neophytou M., Georgiou E., Fyrillas M. M., Choulis S.A., "Two step sintering process and metal grid
design optimization for highly efficient ITO free organic photovoltaics", Solar Energy Materials and
Solar Cells, vol. 122 , pp. 1-7.(2013)
Acknowledgements: This work was co-funded by the European Regional Development Fund and the Republic
of Cyprus through the Research Promotion Foundation (Strategic Infrastructure Project ΝΕΑ
ΥΠΟΔΟΜΗ/ΣΤΡΑΤΗ/0308/06).
P9
62
A vibrational analysis of pristine and chemically doped Indigoids
Christina Enengl,a Sandra Enengl,
a Jacek Gąsiorowski,
b Eric Daniel Głowacki,
a Matthew
White,a Niyazi Serdar Sariciftci
a
a Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler
University Linz, 4040 Linz, Austria b Center for Surface and Nanoanalytics (ZONA), Johannes Kepler University Linz, 4040
Linz, Austria
The need for cheap, easily-processable electronics has led to the development of organic
semiconductors and recently a lot of effort has been put in the processing optimization for
tuning their physical and chemical properties. Indigoids were found to be promising
candidates to be used as biodegradable and biocompatible materials for development of
organic technologies.1,2
In this work, a detailed spectroscopic characterization of different
pigments from the Indigoid family, such as Indigo and Quinacridone, is presented. The
FTIR as well as FT-Raman techniques were applied in order to determine the vibrational
structure, and the symmetric and asymmetric vibrations were detected. The FT-Raman
spectroscopy was performed on these pigments in the powder form, while the FTIR
measurements were done in the attenuated total reflection (ATR) mode using a thin layer
deposited on the ZnSe crystal used as a reflection element. Furthermore, the in-situ
spectroscopic characterization of different pigments during chemical doping was
performed and presented in this work. Measurements were done using ATR-FTIR
technique in presence of iodine vapors. As a result new infrared active vibrations (IRAVs)
were found together with a broad absorption band connected with a formation of the
polaron.
1. Głowacki, E. D. & Voss, G. & Leonat, L. & Irimia-Vladu, M. & Bauer, S. & Sariciftci, N. S.
Indigo and Tyrian Purple – From Ancient Natural Dyes to Modern Organic Semiconductors. Israel
Journal of Chemistry 52, 540–551 (2012). 2. Głowacki, E. D. & Irimia-Vladu, M. & Kaltenbrunner, M. & Gasiorowski, J. & White, M. S. &
Monkowius, U. & Romanazzi, G. & Suranna, G. P. & Mastrorilli, P. & Sekitani, T. & Bauer, S. &
Someya, T. & Torsi, L. & Sariciftci, N. S. Hydrogen-Bonded Semiconducting Pigments for Air-
Stable Field-Effect Transistors Advanced Materials 25, 1563-1569 (2013).
P10
63
An in-situ FTIR-spectroelectrochemical study of the controlled p-type and n-
type doping of Indigoids for electronic devices
Sandra Enengl,a Christina Enengl,
a Jacek Gąsiorowski,
b Eric Daniel Głowacki,
a Niyazi Serdar
Sariciftcia
a Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler
University Linz, 4040 Linz, Austria b Center for Surface and Nanoanalytics (ZONA), Johannes Kepler University Linz, 4040
Linz, Austria
In recent years, organic electronics focused on the research of biodegradable,
biocompatible and low-cost materials which may ultimately be used in daily life
applications including portable devices. A lot of effort was put in the synthesis of new
materials with these desired properties leading to development of new compounds.
Among many different families of materials, Indigoids have shown remarkable chemical
and physical properties. They have been also successfully applied as natural and nature-
inspired dyes in organic electronic devices.1 In this work, an electrochemical and
spectroelectrochemical characterization of different pigments of the Indigoid family,
among others Indigo and Quinacridone, is performed. To determine the oxidation and
reduction potentials of these pigments cyclic voltammetry was applied.2,3
Spectroelectrochemical measurements were done using FTIR technique working in the
attenuated total reflection (ATR) mode. A thin layer of the pigment was deposited on the
Pt sputtered on a ZnSe crystal and used as a working electrode. In the compartment cell a
small Pt electrode was used as a counter electrode and the Ag/AgCl electrode was used as
a quasi-reference electrode. In the measurement non-aqueous electrolyte, namely a 0.1M
TBAPF6 in CH3CN, was used. In this study, combination of electrochemistry with IR
spectroscopy allows for a more complete analysis of structural and electronic changes
during electrochemical doping of Indigoids. As a result new infrared active vibrations
(IRAVs) were found and discussed.
1. Głowacki, E. D. & Voss, G. & Leonat, L. & Irimia-Vladu, M. & Bauer, S. & Sariciftci, N. S.
Indigo and Tyrian Purple – From Ancient Natural Dyes to Modern Organic Semiconductors.
Israel Journal of Chemistry 52, 540–551 (2012). 2. Irimia-Vladu, M. & Głowacki, E. D. & Troshin, P. A. & Schwabegger, G. & Leonat, L. &
Susarova, D. K. & Krystal, O. & Ullah, M. & Kanbur, Y. & Bodea, M. A. & Razumov, V. F.
& Sitter, H. & Bauer, S. & Sariciftci, N. S. Indigo – A Natural Pigment for High Performance
Ambipolar Organic Field Effect Transistors and Circuits Advanced Materials 24, 375-380
(2012). 3. Głowacki, E. D. & Irimia-Vladu, M. & Kaltenbrunner, M. & Gasiorowski, J. & White, M. S.
& Monkowius, U. & Romanazzi, G. & Suranna, G. P. & Mastrorilli, P. & Sekitani, T. &
Bauer, S. & Someya, T. & Torsi, L. & Sariciftci, N. S. Hydrogen-Bonded Semiconducting
Pigments for Air-Stable Field-Effect Transistors Advanced Materials 25, 1563-1569 (2013).
P11
64
Efficient photochemical isomerization of N,N’-di(t-butoxy carbonyl)indigos –
characterization and applications
Dominik Farka, Eric Daniel Głowacki, Elisa Tordin, Gundula Voss, Niyazi Serdar Sariciftci
Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University
Altenbergerstrasse 69, A-4040 Linz, Austria
We report on the photophysics of highly-soluble N,N’-di(t-butoxy carbonyl)indigos (BOC-
indigos), finding that reversible photochemical trans-cis and cis-trans isomerization reactions
proceed with high quantum yields (0.20 – 0.50). Absorption of wavelengths in the 550-600
nm region induces trans-cis isomerism, while blue light (~420 nm) leads to the reverse cis-
trans process. We find that like their parent indigos, trans-BOC-indigos have low
fluorescence yields (~1×10-3
), while the cis isomers have no measurable emission. Electron
donors and proton donors are both found to strongly quench photoisomerization. Observation
of quenching by proton donors supports the model of ultrafast proton transfer deactivation of
excited states in indigoid molecules. Dissolution of the dyes in glassy polymer matrices does
not significantly impede photoisomerization – with this we demonstrate simple photochromic
polymeric films. Reversible photoisomerism induced by relatively low-energy photons (~2
eV) is the dominant photophysical process in these materials, making BOC-indigo derivatives
interesting for photomechanically-actuated materials.
P12
65
Synthesis and Opto-electronic Properties of 4,10-dibromoanthanthrones
derivatives : 6,12-Bis(amino)anthanthrene Derivatives
Jean-Benoît Giguère,a Jean-François Morin
a
a Département de Chimie and Centre de recherche sur les matériaux avancés (CERMA), 1045
Ave de la Médecine, Université Laval, Québec, Canada G1V 0A6.
Recently, we undertook the functionalization of the commercially available polycyclic
pigment 4,10-dibromoanthanthrone (Vat Orange 3). The anthanthrone scaffold is a cheap
and versatile polycyclic building block with two axis of functionalization: the bromines at
the 4 and 10 positions and the ketones at the 6 and 12 positions. A series of 6,12-
bis(amino) anthanthrene-based conjugated molecules was prepared and characterized
using UV-visible and fluorescence spectroscopy and cyclic voltammetry. The modulation
of the absorption spectra and redox potentials of these molecules is possible by changing
the conjugated moieties linked at the 4 and 10 positions. Moreover, the opto-electronic
properties of these derivatives strongly depend on the moieties attached to the nitrogen
atoms at the 6 and 12 positions.
P13
66
Photo-induced Traps in High-purity Bulk-heterojunction Blends
Marek Havlicek,a Markus Scharber
a
a Institute for Physical Chemistry, Linz Institute for Organic Solar Cells (LIOS),
Johannes,Kepler Univeristy Linz, Altenberger Str. 69, A-4040 Linz, AUSTRIA
In our work we focus on the photo-induced defects in high-purity organic materials used
as an active energy-converting medium for bulk-heterojunction solar cells. Traps induced
by light are investigated in samples in the absence of oxygen, water or other extrinsic
reactants which enables us to identify real effects caused by light irradiation.
Understanding these processes is essential for the development of durable high-quality
organic-based solar cells and photodetectors.
By using Light induced Electron Spin Resonance (LESR) at low temperatures the
distribution of traps can be determided based on the recombination kinetics of the charge
carriers. This very sensitive methode enables us to observe the trap distribution after
different doses of solar irradiation. This investigation allows us to predict the operational
lifetime of investigated solar cell materials under controlled doses of solar irradiation
based on the trap distribution in the active layer.
Those information should be then helpful when choosing the material for durable organic-
based devices. Possibly, selection rules for promissing light irradiation-resistant materials
can be formed.
-400 -200 0 200 400 600 800 1000 1200 1400 1600 1800
0.0
0.5
1.040K
-400 -200 0 200 400 600 800 1000 1200
0.0
0.5
1.060K
Sig
na
l in
ten
sity (
arb
. u
.)
-400 -200 0 200 400 600 800 1000 1200 1400 1600 1800
0.0
0.5
1.0all spectra normalized
Time (s) Figure 2 ESR signal evolution measured in an evacuated quartz tube at the PCBM polaron peak for one of the
highly-purified polymer/fullerene blends under investigation. In this case illumination with diferent doses of
light has no effect on signal evolution.
1. S. E. Shaheen, C. J. Brabec, N. S. Sariciftci, Appl. Phys. Lett. 78 (2001) 841.
2. V. Dyakonov, G.Zoriniants, M. Scharber, C. J. Brabec, R. A. J. Janssen, J. C. Hummelen, N.
S. Sariciftci Phys. Rev. B 59 (1999) 8019.
3. N. A. Schultz, M. C. Scharber, C. J. Brabec, N. S. Sariciftci Phys. Rev. B 63 (2001) 245210.
4. C. Carati, L. Bonoldi Phys. Rev. B 84 (2011) 245205.
P14
67
Biocompatible and Biodegredable Materials for Organic Field Effect Transistors
Mihai İrimia Vladua,b
, Pavel A. Troshinc , Melanie Reisinger
d , Lyuba Shmygleva
c ,
Yasin Kanburb,e
, Günther Schwabeggerf , Marius Bodea
g , Reinhard Schwödiauer
d ,
Alexander Mumyatovc , Jeffrey W. Fergus
h , Vladimir F. Razumov
c , Helmut Sitter
f,
Niyazi Serdar Sariciftcib , and Siegfried Bauer
d
a Joanneum Research Forschungsgesellschaft mbH, Franz-Pichler Straße Nr. 30,
8160 Weiz, Austria b Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University, Altenberger Strasse Nr. 69
Linz,Austria c Institute of Problems of Chemical Physics of Russian Academy of Sciences, Semenov prospect 1, 142432,
Chernogolovka, Russian Federation d Department of Soft Matter Physics, Johannes Kepler University, Altenberger Strasse Nr. 69, 4040 Linz, Austria
e Department of Metalurgical and Materials Science, Karabuk University, Balıklarkayası Mevki, 78050,
Karabük, Turkey
f Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Altenberger Strasse Nr. 69
Linz,Austria
g Institute of Applied Physics, Johannes Kepler University, Altenberger Strasse Nr. 69 Linz,Austria
h Materials Research and Education Center, Auburn University, Auburn,Alabama, 36849, USA
Environmental pollution is one of the main problems of the world now. Increasing amount
of electronic waste is a big problem for the environment. To solve the environmental
problems in this way is enable with the production of biodegradable electronic materials
which are degradable in nature. Organic electronics has huge potential to produce
biocompatible materials.
In this study, for the production of biodegradable and biocompatible organic Field Effect
Transistors (OFET’s) adenine, guanine, glucose, sucrose and lactose are used as dielectric
layer. Semiconductor layers are designed with natural semiconductor materials such as
Beta carotene, Indigo, Vat Orange 1, Vat Orange 3 and Perylene diimide. By using these
materials transistors with an operational voltage as low as 4-5 V, a source and drain
current 0.5 µA and on-off ratio of 3-5 orders of magnitude are fabricated.
Figure1.Transfer and output characteristics of an OFET with an inorganic (aluminum
oxide)-organic(glucose) gate dielectric and perylene diimide as organic semiconductor, μ
= 0.01 cm 2 V
− 1 s
− 1 ; C 0d = 138.8 nF cm
− 2
P15
68
Pentacene thin film transistor characterization under ultra-high vacuum
conditions: The combination of electrical and surface analytical methods
R. Lassnig,a B. Striedinger,
b A. Fian,
b B. Stadlober
b and A. Winkler
a
a Institute of Solid State Physics, Graz University of Technology, Petersgasse 16,
A-8010 Graz, Austria b Materials Division, Joanneum Research, Franz-Pichler-Straße 30,
A-8160 Weiz, Austria
Electronic devices based on organic semiconductors are on the verge of taking over large
shares of markets currently dominated by inorganic systems. While the possibilities to create
and optimize organic devices are clearly present, many of the underlying principles affecting
critical device parameters such as performance and lifetime are not fully understood to the
present date. Several promising semiconducting systems, especially conjugated small
molecules such as pentacene, are not soluble and are therefore thermally sublimated under
high-vacuum conditions. Better understanding of semiconductor growth and degradation
processes is considered essential in order to improve device stability and therefore enable
further applications. In order to contribute a new approach to the vast worldwide research on
organic semiconductors, we present analysis on the formation, structure and stability of the
semiconducting layer in organic field effect transistors, through a unique combination of in-
situ layer deposition, real-time electrical and surface analytical characterization, during and
subsequent to the deposition process itself, with all investigations being performed under
ultra-high vacuum conditions. To reach conclusions about the layer growth, in-situ Auger
electron spectroscopy (AES) and thermal desorption spectroscopy (TDS) were performed
parallel to the electrical investigations. Ex-situ atomic force microscopy, in combination with
in-situ TDS and argon ion sputtering allowed direct connections to be made between growth
mode, morphology and charge transport mechanisms. Another system parameter to control
and modify layer growth not employed in many similar experimental systems is the substrate
temperature which could be set in the range of 120-800K. Of special interest was the onset of
the OTFT functionality as a function of layer thickness combined with sample pretreatment.
While all measurements have been performed on well-established gold bottom-contact
pentacene organic field effect transistors with highly doped silicon substrates and silicon
dioxide as the dielectric, our experimental setup had been designed to allow a wide range of
test device modifications and configurations and therefore a multitude of research
opportunities, all in order to gain insight into the relationship between electrical parameters
and layer morphology and ordering.
2x2 µm AFM picture of pentacene islands consisting of one layer of standing molecules
and transfer characteristics as function of pentacene coverage for USD= -50 V
-50 -40 -30 -20 -10 0 10-3,0x10
-4
-2,5x10-4
-2,0x10-4
-1,5x10-4
-1,0x10-4
-5,0x10-5
0,0
50 Å 5A
100 Å 5A
200 Å 5A
400 Å 5A
I SD [A
]
UG [V]
P16
69
Investigation of Photoelectric Features of Vacuum Deposited Organic Materials
Ir(Fppy)3 and AlQ3 Layers
Brone Lenkeviciute a, Kestutis Arlauskas
a
a Solid State Electronics Department, Vilnius University, Sauletekio av. 9 III building
The single and double organic material layers were vacuum deposited onto by ITO covered
glass substrate and their electrical, photoelectrical and electroluminescence (EL) features were
investigated.
Using photo generated charge extraction by linearly increasing voltage method (photo-
CELIV) the mobility of charge carriers of the order of 10-7
cm2/V·s was measured in
Ir(Fppy)3 layer. Experimental investigation results demonstrated that Ir(Fppy)3 may be used as
emission as well as hole transport material.
The family of Volt-Ampere Characteristic (j-V) of organic material layers was measured. It is
demonstrated that AlQ3 sub-layer upgrades injection of electrons from aluminum (Al) into
Ir(Fppy)3 emission layer.
The EL of single Ir(Fppy)3 layer was observed at 19 V threshold voltage while the EL of
double Ir(Fppy)3/AlQ3 layer was observed at 6V threshold voltage. Investigation showed that
EL in 450 nm to 750 nm wavelength range with comparatively small threshold voltage can be
obtained from the structure formed of only two sequent layers of different organic materials
ITO/Ir(Fppy)3/AlQ3/Al.
P17
70
Natural resin shellac as substrate and dielectric for organic field-effect
transistors
Lucia Leonat,a Eric Daniel Głowacki,
a Mihai Irimia-Vladu
,*a,b,c Günther Schwabegger,
d Helmut Sitter,
d
Siegfried Bauerb and Niyazi Serdar Sariciftci
a
aLinz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University, Altenberger
Strasse Nr. 69, Linz, Austria b Department of Soft Matter Physics, Johannes Kepler University, Altenberger Strasse Nr. 69, Linz, Austria
c Institute for Surface Technologies and Photonics, Joanneum Research Forschungsgesellschaft mbH, Franz-
Pichler Strasse Nr. 30, 8160 Weiz, Austria. d Department of Semiconductor and Solid State Physics, Johannes Kepler University, Altenberger Strasse Nr. 69,
Linz, Austria
Shellac is a natural, biodegradable resin, with excellent electrical insulating properties, as well as good
barrier properties to moisture. Shellac is even edible as it is widely used to coat medical pills. High-
quality smooth layers can be obtained by coating raw shellac from ethanol solutions, followed by
cross-linking at 70°C. The final crosslinked resin is stable to temperatures as high as 200 °C and is
compatible with processing layers from organic solvents on top of it. Shellac films in the thickness
range of tens of nanometers showed dielectric breakdown at 8-9 MV cm-1
. Because of these excellent
properties, shellac can be successfully applied in organic electronics.1 We report organic field-effect
transistors (OFETs) using 500 μm thick shellac slabs as substrates and 30 nm thin layers of shellac as
the dielectric. Two of the most studied organic semiconductors were used, pentacene and C60, showing
hysteresis-free state-of-the-art performance on shellac.
1 M. Irimia-Vladu, E. D. Głowacki, G. Schwabegger, L. Leonat, H. Z. Akpinar, H. Sitter, S. Bauer, and N. S.
Sariciftci, Green Chem., 2013, 15, 1473–1476.
P18
71
Cellulose as biodegradable high-k dielectric layer in organic complementary
inverters
A. Petritz,a A. Wolfberger,
b A. Fian,
a M. Irimia-Vladu,
a A. Haase,
a H. Gold,
a T. Rothländer,
a
T. Griesser,b and B. Stadlober,
a
a Materials-Institute for Surface Technologies and Photonics, JOANNEUM RESEARCH
Forschungsgesellschaft mbH, Franz-Pichler-Straße 30, A-8160 Weiz, Austria b
Chemistry of Polymeric Materials, University of Leoben, Otto Glöckel-Straße 2, A-8700
Leoben, Austria
We report on the natural source based and biodegradable material cellulose on Al2O3 as
ultrathin hybrid high-k dielectric layer for applications in green electronics. Dielectric films of
16 nm cellulose (ε = 8.4) and 8 nm Al2O3 (ε = 9) exhibit low leakage currents up to electric
fields of 1.5 MV/cm. Pentacene and C60 based organic thin film transistors show a well-
balanced performance with operation voltages around 2 V. They are implemented in
complementary inverters with excellent switching behavior, a small-signal gain up to 60 and
with exceptionally high and balanced noise margin values of 82% at ultralow operation
voltage (VDD = 2.5V)1.
This figure shows a schematic structure of a fabricated pentacene or C60 based oTFT with a
16 nm ultrathin cellulose film as gate dielectric.
1. Petritz, A. Wolfberger, A. Fian, A. Irima-Vladu, M. Haase, A. Gold, H. Rothländer, T. Griesser, T.
Stadlober, B. Appl. Phy. Lett. 103, 153303-153307 (2013).
P19
72
Biomimetic Membranes for Solar Energy Utilization
1. Preparation and Characterization
Ali Samieipour,a Elham Kouhiisfahani,
a Christian Neubauer,
b Semjon Galayev,
b
Dieter Meissner a,b
a Dep. of Mat. Sci., Tallinn University of Technology, Ehitajate tee 5 19086, Tallinn, Estonia
b Crystalsol OÜ, Acadeemia tee 15a, 12618 Tallinn, Estonia
Whereas especially in bacterial photosynthesis most of the charge transfer steps are well
investigated, the overall requirements should still be investigated in simplified model systems
in order to distinguish between thermodynamic needs and biological realities. Such a model
system - while at the same time a prototype for practical systems - has been developed by the
authors. Based on very high quality compound semiconductor powders (here CZTS),
monograin membranes are produced and will be modified to also enable proton exchange.
Every semiconductor grain sticks out of the membrane on both sides and has already been
proven to enable photoinduced charge transport through the membrane. Thereby hydrogen
can be produced on one side of the membrane while on the other side sulfide will be oxidized
to form polysulfide1.
Fig. 1 Monograin membrane Fig. 2 Photocatalytic cell to separate oxidation and reduction
The research aims at the direct conversion of solar energy into (storable) chemical energy,
especially the direct splitting of water into Hydrogen and Oxygen and the direct reduction of
Carbon dioxide (CO2) into Hydrocarbons using the semiconductor/ electrolyte contact. One of
the most promising approaches is based on the use of monograin membranes, in which
semiconductor particles are embedded into a polymer film so that they stick out on both sides
of the membranes.
Copper-zinc-tin-chalcogenides (CZTS), especially Cu2ZnSnS4, Cu2ZnSnSe4 and their solid
solutions, often called Kesterites due to their crystal structure, is considered as one of today s
most promising new materials for photovoltaics.2 CZTS powder in this research has been
produced in crystalsol OÜ in diameters of 38-
preparing the membranes, the thickness of polymer has been reduced by etching to below 20
m both sides.
1. Meissner, D., Memming, R; Kastening, B. Light Induced Generation of Hydrogen at CdS-Monograin
Membranes, Chem. Phys. Lett. 96 (1983), 34 – 37
2. Meissner, D. Photovoltaics Based on Semiconductor Powders, in: A. Méndez-Vilas (Ed.): Materials and
processes for energy: communicating current research and technological developments, Energy Book Series
#1, Formatex Research Center, Badajoz, Spain, 2013, pp. 126 - 141
P20
73
Structure and Photovoltaic Performance of Anilino Squaraines
Manuela Schiek,a et al.
a Institute of Physics, Energy and Semiconductor Research Laboratory,
University of Oldenburg, D-26111 Oldenburg, Germany
Small molecular semiconductors such as squaraines are advantageous compared to
polymeric materials because they are instrinsically monodisperse, straightforward to
synthesize and to purify. Minor structural variations impact aggregations behavior and
thus solid state optoelectronic properties, so that they are ideal candidates for structure-
property relationship studies. Squaraines are environmentally stable and non-toxic.
Different 1,3-bis(N,N-substituted-2,6-dihydroxy-anilino)squaraines with varying terminal
N-alkylation, (linear and branched, also including a stereogenic center) are investigated as
single crystals, in thin films and blended with a fullerene acceptor as active layer in bulk
heterojunction organic solar cells.1
In case of a chiral squaraine, unusual formation of stereoisomer co-crystals is revealed by
X-ray diffraction. Casted thin films are either amorphous or adopt a thin film crystal
phase. They show characteristic absorbance spectra with H- and J-band signatures, which
correlate with external quantum efficiency measurements of photovoltaic cells. The low
charge carrier mobility of the squaraines is reflected in space charge limited
photocurrents, which is a limiting factor for the solar cells. Also architectural aspects such
as anodic interfacial layers impact the device performance.
The extended focus microscope (Olympus) image on the left side shows the golden
reflectance of a 1,3-bis(N,N-di-isobutyl-2,6-dihydroxy-anilino)squaraine single crystal.
The structural formula of this model squaraine is graphed on the right side.
1. S. Brück, C. Krause, R. Turrisi, L. Beverina, S. Wilken, W. Saak, A. Lützen, H. Borchert, M. Schiek, J.
Parisi, Structure–property relationship of anilino-squaraines in organic solar cells, Phys. Chem. Chem.
Phys. 16, 1067- 1077 (2013).
P21
74
Novel Human-Device Interfaces: Hydrogel EKG Electrodes and Microfluidic
Sweat Monitoring
Timothy Shay, Daniel Morales, Michael D. Dickey, Orlin D. Velev
Department of Chemical and Biomolecular Engineering
NC State University, 911 Partners Way, Raleigh, NC 27695, USA
Growing and aging populations have emphasized the need for low cost medical
diagnostic tools. Wearable biosensors could reduce hospital and clinic visits while lowering
costs associated with staffing and equipment. These sensors require means of continuous skin
interfacing and sampling. We use hydrogels as a novel biomimetic interface for early
prototypes of wearable health monitoring devices. The goals include constructing new
electrocardiogram (EKG) electrodes and sweat capture devices.
To obtain a strong heart’s electrical signal from the body for an EKG, a low resistance
electrode with a low impedance device-skin interface is needed. A four point probe
conductivity test was initially performed on polyacrylamide hydrogel patches to determine
their bulk resistance. The inclusion of ionizable groups on the hydrogel molecular backbone
lowered the resistance by two to three orders of magnitude, by ionic conductance mechanism.
These electrolytic hydrogels were then interfaced with a copper wire encased in PDMS to
create an EKG electrode, which was able to provide a low-noise EKG on a human subject.
We will discuss the ongoing work on optimizing the impedance of the hydrogel-skin interface
and investigating whether a liquid metal such as eutectic liquid gallium (EGaIn) could be used
to create a truly flexible electrode.
Continuous non-invasive sweat collection allows sampling and monitoring of many
analytes such as glucose, cortisol, and various ions that provide a non-invasive measure of the
body’s overall health. The hydrogel patches can be tuned to create osmotic pressure gradients
while in contact with the body to promote fluid intake for sweat capture. To understand the
hydrogel’s ability to work as a sweat collection interface, both the diffusion through the gel
and intake of fluid from the body was characterized. Diffusion of acidic solutions, meant to
mimic sweat, was measured via a pH color change indicator. The diffusion penetration
profiles were successfully modeled with both Matlab and COMSOL computational packages.
The ability of the hydrogel in a superporous form to draw water from skin was demonstrated
on a peach model. Water intake rates were measured and correlated to both water content of
the hydrogel and peach. The two hydrogel interface functions were then combined to create a
pH color change sensor that
detected the acidity of a peach.
Future sweat capture work
includes combining both the
intake and evaporation from
hydrogels with microfluidic
networks to create an osmotic-
capillary pump that can deliver
continuously sweat samples to
embedded sensors. Work will
also be performed to measure
body hydration levels based
impedance measurements in the
hydrogel patches.
P22
75
PEDOT-based electrochemical transistor
M.K. Sheliakina, N.I. Crăciun, P.W.M. Blom
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
Recently, π-conjugated polymers have been studied for a variety of applications such
as field-effect transistors, light-emitting diodes, solar cells, electrochromic devices,
electronic circuits, sensors, and other devices. Poly(3,4-ethylenedioxythiophene)
(PEDOT) is an electrically-conducting conjugated polymer that has very good
conductivity and demonstrates biocompatibility. Thus it is considered as one of the most
important and widely used polymers. Organic electrochemical transistors (OECT) based
on PEDOT:PSS have already been proven to be suitable candidates as transducers for
various biosensor applications. Here the electrical conductivity of PEDOT:PSS is changed
by (de)doping due to the incorporation of ions. In this work OECT based on PEDOT:PSS
have been studied. Transistor test devices were fabricated with heavily doped n++ Si
wafers with 200 nm thermally grown SiO2 as gate dielectric. Au source and drain
electrodes were defined using conventional photolithography. Ti was used as an adhesion
layer. The channel length is 10μm and the width is 10mm. A PDMS structure was glued
on the substrate to confine the electrolyte and insulate the contacts from the electrolyte
solution (a 1M NaCl solution). A gold wire immersed in the electrolyte is used as the gate
electrode. The channel of the transistors consisted of a 60-nm thick film of PEDOT:PSS
spin coated onto the substrate surface. The working characteristics of the OECTs have
been investigated. Transfer and output characteristics of the transistors were obtained and
analyzed.
P23
76
Preparation and Application of Functionalized Protein Fibers
Niclas Solin
Department of Physics, Chemistry, and Biology (IFM), Biomolecular and Organic
Electronics, Linköping University, 581 83 Linköping, Sweden
Proteins have a rich supramolecular chemistry, and may self-assemble into a variety of
ordered aggregates. A prominent example is the aggregation of proteins into protein wires,
known as amyloid fibrils. These have very attractive mechanical properties and are thus
investigated for various applications.1 We have focused on the self-assembly of insulin into
such structures. When exposed to acid and heat, insulin readily forms amyloid fibers. These
fibers can be used as templates in materials science applications. We have developed methods
that allow us to functionalize such protein fibers with phosphorescent metal-complexes.2 The
method involves mixing the metal complex and the protein in the solid state, followed by self-
assembly of the resulting composite material. We can successfully fabricate white OLEDs
incorporating these materials.3,4
We have extended the scope of the method to include various
types of hydrophobic molecules and materials, including magnetic nanoparticles.5,6
We can
thus prepare biomolecule-based materials with different functionalities and morphologies and
we are investigating various applications for such structures.
1. Knowles, T. P. J. & Buehler, M. J. Nanomechanics of functional and pathological amyloid materials.
Nature Nanotech. 6, 469-479 (2011).
2. Rizzo, A., Inganäs, O. & Solin. N. Preparation of phosphorescent amyloid-like protein fibrils. Chem.
Eur. J. 16, 4190-4195 (2010).
3. Rizzo, A., Solin, N., Lindgren, L. J., Andersson, M. R. & Inganäs, O. White light with phosphorescent
protein fibrils in oleds. Nano Lett. 10, 2225-2230 (2010).
4. Solin, N. & O. Inganäs, Protein nanoffibrils balance colours in organic white-light-emitting diodes. Isr.
J. Chem. 52, 529-539 (2012). 5. Solin, N. Amyloid-like fibrils labeled with magnetic nanoparticles. Biomolecular Concepts, 4, 425-432
(2013).
6. Andersson, B. V., Skoglund, C., Uvdal, K. & Solin, N. Preparation of amyloidlike fibrils containing
magnetic iron oxide nanoparticles: effect of protein aggregation on proton relaxivity. Biochem. Biophys.
Res. Commun. 419, 682-686 (2012).
P24
77
Indigo-based polymer: a different synthetic way
Elisa Tordin, Dogukan Hazar Apaydin, Zeynep Bozkurt, Eric Daniel Głowacki, Gundula
Voss, Niyazi Serdar Sariciftci.
Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler
University Altenbergerstrasse 69, A-4040 Linz, Austria
Indigo is a well-known dye with a reversible redox behavior. The ability of indigo to
accept two electrons and be converted in its leuco-form, together with the very high
stability of the oxidized form, make it an interesting candidate for the preparation of
polymers with a donor-acceptor alternated structure. Among the all the possible available
synthetic ways, we focused our attention on the preparation of bis-thienyl indigo
derivatives via Stille coupling followed by electropolymerisation and electrochemical
characterization on the working electrode. A new synthetic way for the diiodo-indigo,
precursor for the Stille coupling, has been developed by modification of the synthesis of
indigo from anthranilic acid.
P25
78
Polytetrafluoroethylene (PTFE) surface properties tunning by extreme
ultraviolet (EUV) irradiation
Inam Ul Ahad,a,b
Bogusław Budner,a Tomasz Jan Kałdoński,
c Andrzej Bartnik,
a Henryk
Fiedorowicz, a and Dermot Brabazon
b
a Institute of Optoelectronics, Military University of Technology, 00-908 Warsaw, Poland b Advanced Processing Technology Research Centre Dublin City University, Dublin 9,
Ireland Department 2, University 2, Address 2 c Institute of Motor Vehicle and Transportation, Military University of Technology, 00-908
Warsaw, Poland
Mico and nano- surface texturing on polymeric biomaterials surfaces enhance the degree of
biocompatibility.1 Extreme ultraviolet (EUV) radiation extending wavelengths from about
5nm to 50nm make possible to write nano-patterns on the surface of polymers. Moreover
functionalization of polymeric biomaterials is also possible by introducing reacting gases
(such as nitrogen) during EUV irradiation. Recent studies by our group demonstrate
successful surface micro- and nano-structuring and functionalization of EUV treated polymer
samples.2 Easy fabrication of Polytetrafluoroethylene (PTFE) in various forms such as tubes
and strands make it appealing material for cardiovascular prostheses. However low degree of
biocompatibility has been reported due to comparatively low free energy and thrombogenic
surface.3 In this study, PTFE films have been irradiated with a laser-plasma EUV source
based on a double-stream gas-puff target, irradiated with the 3 ns/0.8J Nd:YAG laser pulse at
10Hz. The PTFE samples were irradiated with EUV photons in the presence of nitrogen gas
which resulted in the formation of pronounced nano and micro-textured surfaces (see figure
1). The roughness analysis of the AFM images shows an increased surface roughness up to
many folds. Water contact angle measurement demonstrate increased hydrophobicity which
helps in better cell adhesion. Successful incorporation of nitrogen atoms on the upper layer
surface observed in XPS scans which promotes cell attachment.
Figure 1:AFM images of PTFE samples (a) pristine (b) EUV modified
References:
1. Ahad, I. U., Bartnik, A., Fiedorowicz, H., Kostecki, J., Korczyc, B., Ciach, T., &
Brabazon, D. Surface modification of polymers for biocompatibility via exposure
to extreme ultraviolet radiation. J Biomed Mater Res Part A
(DOI: 10.1002/jbm.a.34958) [article in press]
2. Bartnik, A, Lisowski, W., Sobczak, J., Wachulak, P., Budner, B., Korczyc, B., &
Fiedorowicz, H., Simultaneous treatment of polymer surface by EUV radiation and
ionized nitrogen Appl.Phys. A 109 39–43 (2012)
3. Jagur-Grodzinski, J. Biomedical application of functional polymers. React. Funct.
Polym. 39, 99 (1999)
(a) (b)
P26
79
Nature-Inspired Semiconducting Pigments for Organic Electronics
Cigdem Yumusak1, Eric Daniel Głowacki
1, Giuseppe Romanazzi
2, Uwe Monkowius
3, Halime
Coskun1, Nevsal Sunger
4, Gundula Voss
1, Niyazi Serdar Sariciftci
1
1Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University of
Linz, A-4040 Linz, Austria 2Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e di Chimica (DICATECh),
Politecnico di Bari, Via Orabona 4, 70125, Bari, Italy 3Institute of Inorganic Chemistry, Johannes Kepler University, A-4040 Linz, Austria
4Solar Energy Institute, Ege University, Bornova-Izmir, Turkey
Many natural dyes and pigments are based on hydrogen-bonded -stacked organic molecules.
These molecules are very promising semiconducting materials because of remarkable physical
and chemical properties as well as low-cost production of biocompatible, biodegradable, and
sustainable electronic devices. An example is epindolidione which is from the indigo family
and we present in this report its electrochemical and optical properties together with its two
derivatives, their crystalline structure, their stability in air and water and results from organic
field effect transistors (OFETs) and organic light emitting diodes (OLEDs).
P27
80
Notes
81
Notes