empanews august 2012

The man, who tamesvibrating bridges 22

Medical technology:Friendly implants 10

A “green” factory that isearning money 26

Magazine for Research, Innovation and Technology TransferVolume 10 / Issue 37 / August 2012

EmpaNews

Empa goes to space

02 // Editorial

The art of solderingEmpa composites on their wayto Mercury 04

At ease in all dimensions

CERN researchers recently obtained the first hints ofthe elusive Higgs particle in the “Large Hadron Col-lider”; around the same time Nasa was spreading

breathtaking panoramic pictures from Mars, taken by the“Mars Exploration Rover”. Two breakthroughs from op-

posite ends of scientific research, as it were:the unimaginably small in the case of the el-ementary particle, and the staggeringlylarge, i.e. our universe.

Empa is also working in both dimen-sions in applied research. For instance,Empa technology can be found aboard the“comet chaser” Rosetta, an ESA satellitethat will be reaching its destination, thecomet 67P/Churyumov-Gerasimenko, in2014. The BepiColombo Mercury mission,which is due to take off in 2015 and re-

search the innermost planet of our solar system, also has“Empa inside” (see page 4).

The other “end”, i.e. the micro- or nanometer range,is important for, among other things, the developmentof innovative products in medical technology. In thecurrent “Focus” we will introduce you to several exam-ples from our laboratories – just in time for the inaugural“World Medtech Forum” in Lucerne in late September,for which Empa is acting as “Innovation Partner”. Toname but one example, the institute will be exhibitingnew microstructured implant surfaces, which ensurethat cells “feel at home” on the implant, grow better andthus hold on tight to it.

Our MedTech activities also exemplify how closelywe work together with partners from industry in orderto ultimately turn our research results into marketableinnovations – including the motivational “friction” thatoccurs when inquisitive researchers eager for knowl-edge collaborate with developing engineers from indus-try who are geared to achieving commercial success (seeinterview with Synthes CTO Robert Frigg on page 18).

Enjoy reading!

Michael HagmannHead Communications

Cover

Starting in 2022, the MercuryMagnetospheric Orbiter (MMO) willorbit Mercury for a year. On board:an especially lightweight massspectrometer whose heatable ionizationunit was fabricated at Empa.

Contents // 03

Solar cells in motionA new work of art celebrates thebeauty of eco-technology 29

Quite on deckFelix Weber calms downswaying bridges 22

Implants reinventedInnovative surfaces promotecell growth 10

Research and development04 Precision on the way to Mercury Specially soldered parts from the Empa labs fly into space

06 Space technology for old buildings Aerogel plaster reduces heating costs and preserves looks

08 Hydrogen is mobilizing Three Empa demonstrators make an appearance in St.Gallen

Focus: Medical technology

10 Friendly implants How metal surfaces encourage cell growth

14 A band-aid with many talents The next generation of wound dressing administers drugs

16 Medical technology – made by Empa 13 research projects at a glance

18 “Empa's passion is to understand a problem” Interview: Robert Frigg, CTO of implant manufacturer Synthes

21 Corrosion in the human body Why implants fail, and what Empa is doing about it

Knowledge and technology transfer

22 The taming of the vibration How an Empa engineer is calming bridge decks and cables

25 Nano in coats of paint: a good idea? A research projects analyses the risks of nanoparticles

26 A “green” factory that is earning money How manufacturing can be made more ecological

Imprint

PublisherEmpaÜberlandstrasse 129CH-8600 DübendorfSwitzerlandwww.empa.ch

Text & DesignCommunication

ContactPhone +41 58 765 47 [email protected]

Published quarterly

ISSN 1662-7768

04 // Research and development

Off to Mercury!

When the BepiColombo mission takes off for Mercury,Empa components will be on board the satellite.The specially soldered components of a mass spectrometerwill withstand the chilling journey through space aswell as the baking temperatures when orbiting Mercury.

TEXT: Rainer Klose / PICTURES: Empa, ESA

When an Ariane 5 rocket takes off in August 2015 totransport the “BepiColombo” probe of the “Euro-pean Space Agency” (ESA) to Mercury, it will be

equipped with know-how and precision work of an Empa lab-oratory: The ionisation equipment of a mass spectrometer, re-sistant to heat and cold, yet extremely light and reliable, wasmanufactured by Hans Rudolf Elsener, an expert for joiningtechnologies. The probe will orbit Mercury for two years andanalyse traces of chemical substances from a height of 400kilometres, which should give researchers an indication ofhow the inner planets of our solar system were formed.

It's going to be a real temperature roller-coaster. The meas-uring instrument must withstand temperatures of down to minus150 degrees C during the seven-year trip to Mercury. Once it ar-rives in orbit, the satellite will then be “grilled” by the sun. Thetemperature inside the detector will then rise to more than 300degrees C. The Physical Institute of the University of Berne ap-proached Elsener to help with the manufacture of a heatable com-ponent. As well as the temperature difference, weight also playsa decisive role on interplanetary missions. The “Mercury Magne-tospheric Orbiter” (MMO) probe carries the instruments for fivedifferent experiments – but it must not weigh more than 45 kilo-grams.

Elsener and his team were to construct a semicircular, elec-trically heated support structure, which is needed to efficientlyionise neutral particles flying around in space. These ions are gen-erated at coated conversion surfaces at the entrance aperture of

the mass spectrometer, and pulled in by an electrical field. Peri-odic heating of these surfaces removes organic residues and im-proves the efficiency of the mass spectrometer. The entire sur-face of the aluminium oxide heating element is fixed toa stable metal carrier. Theoretically, a carrier madefrom niobium would be ideal, since this grey,shiny ductile metal has a similar thermal ex-pansion coefficient to aluminium oxide.However, niobium is too heavy for theprobe. Elsener and his team thereforedecided to use a carrier made from ti-tanium, which was half the weight.The entire component now weighs nomore than 40 grams.

The art of solderingBut the use of titanium also entailedsome problems: It expands muchmore than aluminium oxide whenheated. The heating element must there-fore be soldered on using a suitable mate-rial, so that it does not detach from the car-rier because of the temperature fluctuations dur-ing the trip. At the same time, the temperature dur-ing the soldering process must not be too high – otherwisedestructive tension occurs in the material combination, al-ready at the manufacturing stage.

Research and development // 05

Soldering is the only way of connecting different metalsto each other if strength, good heat transmission and heat re-sistance are required. And the wealth of know-how about sol-

dering procedures that is available at Empa is rarelyfound in Switzerland, if anywhere. It was quickly

clear to Elsener and his colleague ChristianLeinenbach that they would not get far with

the usual methods, which are mainly usedin mechanical engineering. Afteranalysing different substance groups,they homed in on an alloy made fromgold and germanium. The soldermelts at about 360 degrees C and, af-ter hardening, is less brittle than analloy made from gold and silicon, forexample. The disadvantage: The ex-otic material is hard to find. Hans

Rudolf Elsener had to have a 25 mi-crometer-thick foil tailor-made by a sup-

plier in the USA.

Titan, Tungsten, GoldIt is virtually impossible for a layman to compre-

hend how complex the soldering process is, even witha suitable solder. It requires a number of additional layers tomake a perfect connection: A layer made from chromium-nickel, followed by a layer of titanium-wolfram and a thin lay-

er of pure gold is needed to prepare the aluminium oxide.Likewise, the titanium carrier is coated with nickel and gold.In order to improve adhesion the layers must be baked ontothe subsurface in a vacuum furnace at 500 degrees C (tem-pered, as the experts say). Only then can the gold-germaniumsolder firmly connect the components. The Empa experts dis-covered the perfect combination of all methods using sheartests with small test objects. First a prototype of the compo-nent was manufactured and subjected to both vibration andthermocyclic tests. It passed the tests without any problemswhatsoever. Elsener and Leinenbach then manufactured “thereal thing” – a flying model to go on the satellite and a sub-stitute.

A long, long journeyThe BepiColombo satellite mission, named after an Italianmathematician and space pioneer, consists of three segments:a European and a Japanese orbiter and an ESA drive module,which transports the two probes to Mercury. The entire unitwill be six metres high and will weigh about four tons – aboutone-third of which is fuel. The Empa component will fly inthe Japanese satellite. The space probe will reach Mercury inJanuary 2022, send the two orbiters into orbit around theplanet and radio information to Earth. If everything goes asplanned, we will know more about the surface chemistry, thecore and the magnetic field of Mercury – and also a little bitmore about the history of the creation of our solar system. //

The “BepiColombo” space probe’strip to Mercury will take years.The instrumentation must be aslight as possible and withstandextreme heat and cold. Hans RudolfElsener developed the solderingtechnology for a particularlysensitive component, which is madeof ceramic and metal.

A heatable ceramic structurefrom Empa’s laboratory.

67

110

70 70 7085

75 80

130

9075 70

27 33

Samples made by different manufacturers

Styr

ofoa

m-P

anel

Aer

ogel

-Pla

ster

Thermal conductivity of currently used insulating renders [mW/(m•K)]


Old buildings are beautiful – and hard to insulate.Empa has developed a new Aerogel-based plasterthat provides twice the insulation of currentlyused insulating renders. The product should comeonto the market next year.

TEXT: Rainer Klose / PICTURES: Joachim Kohler; Fixit / ILLUSTRATION: Empa

Space technologyfor old buildings

1A comparison of insulation valuesfor insulating render. The red barrefers to the Aerogel render: ithas insulation values similar tothose of polystyrene panels (blue).

2A historic timber-framed house inKreuzlingen: those who would liketo insulate the building’s wallswithout marring its visual appear-ance often are not able to turn toinsulating panels. Insulating renderis the solution.

3 A sample of the Aerogel render issprayed on with a professional ren-dering machine and then smoothedout. In the next step, the softrender will have to be protectedwith a tough surface layer.

1

3

There are one and a half million old buildings inSwitzerland. We have to live with these buildings –indeed we want to live with them. Yet at the same

time the country's energy consumption is increasing. Ac-cording to the Federal Office of Energy, 4.5 million tonnesof light fuel oil and 3 million cubic metres of natural gas areimported every year, 43 percent of which goes up the chim-ney for heating. Anyone who wishes to cut down on fossilfuels must therefore insulate their home. But how do I in-sulate my historical building – be it a timber-framed housein Thurgau, a town house in Solothurn or an art-deco apart-ment building in the north of Zurich? Heritage protectionwould be none too pleased if the historical façade was sim-ply boarded with modern insulating panels.

Rendering is the most suitable way of maintaining thelook of an old house. Cutting insulating panels to size (andshape) is also a cumbersome business when lining windingstaircases, round arches and supporting walls. “An innerlining of insulating render is considerably quicker to apply,”says Empa building physicist Thomas Stahl. “The renderalso lies directly on the brickwork and does not leave gapswhere moisture could condense.”

Stahl has made it his task to take the insulating prop-erties of render to a new level, and to develop a render thatprovides as much insulation as a polystyrene board. Yearsof research have now finally paid off: The product, which

2


http://youtu.be/5zf_mj3L6Y8For smartphone users: scan the QR code(e.g with the “scanlife” app)

Video:Aerogel render isbeing applied

-

LUMOSFT-IR-Mikroskopie leicht gemacht

Eigenständiges FT-IR-Mikroskopmit Voll-Automatisierung

Höchster Komfort in der Bedienung

Motorisierter ATR-Kristallmit integrierter Druckkontrolle

Messungen in ATR, Transmission und Reflexion komplett automatisiert

Hohe Qualität der visuellen undIR-spektroskopischen Ergebnisse

Weitere Informationen finden Sie unter:www.brukeroptics.de • www.lumos-ir.de

Innovation with IntegrityF T- IR

Tel: (+41) (44) 825 9818E-Mail: [email protected]

has been developed jointly with Swiss render manufacturerFixit, has come through laboratory testing, and initial trialson buildings started in July 2012. According to Fixit, if thenew insulating render holds up to its promise, the materialcould come onto the market in the course of next year.

World record for insulatorsBut what does this marvellous render from the Empalabs consist of? Stahl and his colleagues decided on thebest insulating material that can be produced industri-ally: aerogel. The material, which is known as frozensmoke” because of its appearance, consists of around 5percent silicon – the rest is air. Aerogel was used backin the 1960s for insulating space suits, and has 15 en-tries in the Guinness Book of Records, including “bestinsulator” and “lightest solid”.

Aerogel is already being used in the building industry,as cavity-injected wall insulation or in the form of insulat-ing boards made from fibrous fabrics. So where is the prob-lem? Why hasn't anybody already mixed aerogel with ren-der? Thomas Stahl doesn't waste his breath on a lengthyexplanation. He takes a transparent plastic box off the shelfand opens the lid: “Put your hand in and rub it a little.” Theaerogel globules really are extremely light, almost weight-less, and can be held between thumb and forefinger. Butas soon as you rub your fingers, it crumbles. After two orthree rubs, a fine powder is all that remains of the wondermaterial. “And that was precisely our problem”, says Stahl,“if we mix the powder with water and apply the render byhand, the results are good. But imagine if the render wasblown through the hose of a professional rendering ma-chine at a pressure of 7 to 8 bar. There wouldn't be muchleft of our aerogel.”

In order to make the render “machine-compatible”,a tremendous amount of knowledge about the contentsof dry render mixtures and their interactions with aero-gel was required. And a series of tests – from palm-sizedlaboratory samples to weathering tests lasting formonths. Eventually Stahl found a solution, which henow wants to have patented.

The samples of the aerogel render exhibited a heat con-ductivity of less than 30 mW/(mK) – twice as much insu-lation as the insulating render that is currently commercial-ly available (see bar diagram on left). If the innovation as-serts itself on the market, Swiss house owners will soon seea considerable reduction in fuel consumption. //

On the road –with hydrogen

At the end of May, two vehicles and a portable living andworking module got together in front of the Empa prem-ises in St. Gallen: the “hy.muve” street sweeper, a fuel

cell-driven bus and the “Self” container. They all have one thingin common: the use of hydrogen as an energy source. Both streetsweeper and bus use it as fuel, and “Self” uses its own “hydrogenplant” to generate (and store) energy in summer, which can lateron be used for cooking and heating.

“hy.muve” is clean, makes cleanThe “Bucher Schörling CityCat H2” hydrogen-powered streetsweeper that was developed by Empa in collaboration with PSIand industrial partners, had been tested on the streets of Basel forthree years. The advantage: It emits only water vapour as exhaustand is extremely quiet. In April 2012 the system and the vehiclewere relocated to St.Gallen for another real-world assessment.Here it will be all about testing the municipal vehicle, which hasby now overcome its teething troubles, in everyday use, gainingmore experience in the use of the vehicle and examining the age-ing behaviour of the different components.


1 2

TEXT: Martina Peter / PICTURES: Empa


Bus saves energy and protects the environmentFive busses powered by fuel cells are currently being operated inBrugg in the canton of Aargau. Postauto Schweiz AG also recentlyopened a hydrogen filling station. PSI and Empa are on board as re-search partners. Empa's role during the testing phase is primarily ofan advisory nature. Empa scientists examine the efficiency of hydro-gen production, its incorporation in the electricity market and gathersexperience in the construction of hydrogen filling stations for futureprojects.

Independent living and working in “Self”“Self”, a modern room module for living and working that is inde-pendent of energy and water, was also available for inspection in St.Gallen. Hot meals are prepared on a hydrogen-powered kitchenunit. Hydrogen is produced via electrolysis of water, and the electri-cal energy for this is generated using solar cells on the roof. Untilthe hydrogen is needed it is temporarily stored in containers filledwith metal hydrides, another new development from Empa. Empaand Eawag are testing new building concepts as well as energy andwater management technologies in “Self”: very little complies withthe current state of technology; almost everything consists of speciallydesigned and conceived components, such as the building shell. //

1A bus with a fuel-cell drive sitsproudly in front of the glass-encased Empa building inSt.Gallen. Empa offers itsexpertise to advise localauthorities and cantons in theplanning of a new hydrogeninfrastructure.

2The “hy.muve” hydrogen-driven road sweeperdeveloped at Empa hasalready been tested in Baseland is currently cleaningthe streets in St. Gallen. Addi-tional Swiss cities will follow.

3 Self-sufficient “Self” roommodule: The living andworking container generatesand stores the energy forits inhabitants, year round.

http://youtu.be/Xo6qCvkNyq0For smartphone users: scan the QR code(e.g with the “scanlife” app)

Video:A hydrogenpowered bus

3

Friendly implantsCell biologists at Empa want to “tune” implants such that they canbetter carry out their tasks in the human body. The surface of the implant is the key to success. Together with the Fraunhofer Institute IFAM, the Empa team developed a method to manu-facture implants with the required surface “from a single cast”.

TEXT: Martina Peter / PICTURES: Empa, Synthes

Focus: Medical Technology // 11

In order to encourage the human body to accept an implant, itssurface should be readily inhabitable by (future) neighbouringcells. Osteoblasts, i.e. cells that are responsible for bone forma-

tion, must be able to attach to an artificial hip joint so that new bonesubstance forms, thereby firmly anchoring the implant in the bone.Researchers at Empa are working to develop micro-structured im-plant surfaces that provide the bone cells with the best possiblegrowth conditions. Arie Bruinink, cell biologist in the “Materials-Bi-ology Interactions” laboratory, explains: “Amongst other things, wehave seen that a surface structure with near cell-sized dimples hasa considerable effect on cell shape and adhesion.”

The scientists can observe how cells respond to different mod-el surfaces with a confocal laser scanning microscope, amongstother things. Once the bone marrow cells had been disseminatedonto a metal probe with a dimpled surface, they adhered to thematerial, formed their cell skeleton or cytoskeleton, and adaptedtheir shape to the surface structure. On a surface with dimpleswith a diameter of 30 or 50 micrometres and 20 micrometres apart,the cells stretch between the dimples and are no longer as flat asthey normally appear in a culture dish. Bruinink believes that thisis a very conspicuous behaviour, the effects of which on cell dif-ferentiation should be investigated further.

Pore-free cleanliness – and still favourableIn order to manufacture implants in innovative ways, he initiallydeveloped a metal injection moulding (MIM) procedure with col-leagues from the Fraunhofer Institute for Manufacturing Technol-ogy and Applied Material Research (IFAM) in Bremen. This allowsthe implant and its microstructured, biocompatible surfaces, to be

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12 // Focus: Medical Technology

manufactured in “a single cast”. According to Bruinink, the aimof the project, financed by the Volkswagen Foundation, is to cre-ate surfaces that can be structured with (sub)micrometer accuracy– a precision that has hardly been possible to date; it takes a con-siderable amount of money and effort to manufacture structureslike this. During implant manufacture it is also important that nounwanted pores form on the surface, in which germs could hide.These can cause infections and chronic inflammation – with thepossible consequence that the implant will have to be removedagain. Bruinink is pleased with the new MIM method, since it hassucceeded in creating a precisely structured, pore-free surfacesimply and cost-effectively.

A patented method – and not just for the medtech sectorThis method, which has now been patented, is not only suitablefor materials in the medtech sector. The material’s outstandingmechanical properties (high density and nanostructured design)are also interesting for other applications. The method couldtherefore be used in almost any situation where materials withgreater strength and hardness are required, such as gears and shippropellers.

This method, which has now been patented, is not only suit-able for materials in the medtech sector. The material’s outstand-ing mechanical properties (high density and nanostructured de-sign) are also interesting for other applications. The method couldtherefore be used in almost any situation where materials withgreater strength and hardness are required, such as gears and shippropellers. //

1Empa researchers Arie Bruinink andMagdalena Obarzanek-Fojt in thelab looking at a computer screen toexamine how well the cells havepopulated the test object’s surface– and which surface structuresfavour cell growth.

2One of the test objects with a micro-scopically fine dimpled surface.

3This is how cells adhere to the struc-tured surface.

Publication

M. Bitar, V. Friederici, P. Imgrund, C.Brose, A. Bruinink: In vitro bioactivityof micro metal injection mouldedstainless steel with defined surfacefeatures, in: European Cells and Ma-terials, Vol 23, May 2012 (pages 333-347)http://www.ecmjournal.org/journal/papers/vol023/pdf/v023a26.pdf

http://youtu.be/sjERN3PLFWI For smartphone users: scan the QR code(e.g with the “scanlife” app)

Video:Cell biologistsdiscuss theirwork

>>

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2 3


Medical technology hasbeen one of Empa'smain research areas for

more than 10 years. For a materi-als research institute such asEmpa, the main focus is on thecontacts and interactions be-tween man and natural and arti-ficial materials; more and more of these substances and parti-cles are impinging on or even being implanted in our bodies.The demand for applications on and in the human body is aparticular challenge for the area of materials development. It isnot just a case of making materials resistant and long-lasting,that’s a sine qua non; they must also be bio-compatible, i.e.compatible with the human organism, and should adapt to theconditions in our body in an ideal way – without having anyadverse effect.

Empa develops materials for “spare parts” that fulfil currentrequirements of our society, which, on the one hand, is becomingincreasingly older; on the other hand, many new sporting andleisure activities (some of which are quite dangerous) are leadingto increasing numbers of younger patients. This means that a sig-nificantly longer service life is required (durability, corrosion re-duction), a better integration (interaction with the organism andthe surrounding tissue) and new ways of manufacturing andtreating the implant surfaces (functionalisation, coating). Testingin biological systems is also part of the development of these ma-terials, so that biological compatibility can be guaranteed.

Empa investigates these topics in its laborato-ries. The intensity, with which we do this, is shownby one simple figure: nine of the 29 research labsare involved in medical technology in the broadestsense. The Empa researchers go about their workin an extremely collaborative fashion, since theproblems that occur when materials are installed inthe human body or used directly on the human

body can only be solved using interdisciplinary cooperations. Engi-neers, physicists and chemists, but also biologists, materials scien-tists and experts from other disciplines are involved in order to ex-amine the problems in an integrated way, so that as many aspectsof materials usage in the medtech area as possible can be covered.

Empa does not just carry out research on these topics withinpublicly-funded projects (for instance, by the Swiss Commission forTechnology and Innovation (CTI) or the EU framework pro-grammes), but also cooperates directly with companies that bringthese developments onto the market as novel products and there-fore strengthen the Swiss economy and competitiveness. In somecases the cooperation is so close that company employees are di-rectly involved in research projects in Empa’s labs and thus canpromptly pass on the results to the industrial partners – a Joint Ven-ture in the best sense of the word!

From materials development to applications, from spareparts in the body to whole body modelling, from medical bene-fits to safety research with regard to potential side effects, Empacovers the whole nine yards and provides a “one-stop shopping”solution for the Swiss medtech industry. //

Medtech@Empa

“Medtech materialsshould adapt to ourbody in an ideal way– without havingany adverse effect.”

TEXT: Harald F. Krug, Empa Board Member / PICTURE: Empa


A band-aid with many talents

The next generation of band-aids and wound dressings could simultaneously reducepain and inhibit inflammation – and dissolve automatically when their job is done.Empa is investigating how such a multi-purpose patch can be produced.

TEXT: Rainer Klose / PICTURES: Beat Geyer, Empa

Nicolas Lavielle is holding athin, white piece of nonwovenfabric in his hand that is as

small as a cotton ball and just as soft.“This is what our experiments are cur-rently producing”, he explains. For hisdoctoral thesis, Lavielle developed apossible manufacturing method atEmpa in St.Gallen for the wound dress-ing of the future. Perhaps it should berenamed: the multifunctional band-aid. Because it should not simply coverthe wound but also release medicationduring the healing process, such asanti-inflammatory drugs or analgesics.And we are not just taking about youreveryday band-aid for minor injuriesthat occur in the kitchen, but dressingsfor professional medicine. This type offabric could be placed on injured skinbeneath a plaster cast, for example.The dressing would do its job for sev-eral weeks, releasing analgesics andanti-inflammatory drugs at the site ofinjury until both bone and wound arehealed and the plaster cast can be re-moved.

Slow release of drugsA basic prerequisite for such a long-lasting effect is that the active compo-nent incorporated in the fabric is notreleased all at once but given off grad-

ually. This can be achieved, for instance,by having a carrier material that slowly dis-solves. Materials of that sort actually do ex-ist in the form of biodegradable plastic suchas polylactide. In the body the sub-stance is broken down into lacticacid and eventually into waterand CO2. However, on the sur-face of the skin the breakdownprocess is significantly slower.

Pulled by high voltageThe method of choice formanufacturing fabric likethis is electro-spinning. Theprocedure has been thor-oughly investigated in recentyears and has even been usedon biological materials: Apolymer solution is drippingout of a thin cannula. The drip-ping speed can be accelerated byapplying an electrical voltage be-tween the cannula and the bottomof the droplet; even threads can bepulled depending on the viscosity of thesolution. At the lower end of their flight thethreads swirl within the electrical field.This means that the material does not landon a neat pile but rather forms a flat fabricof polymer threads. Under the microscope,the product looks like a plate of spaghetti.The solvent has already evaporated during

1A drop of polymer justbefore its “take-off” intothe electric field.

2PhD student NicolasLavielle (above),Matthijs de Geus andAna-Maria Popa duringan experiment.

3Extremely thin threadsresult after being pulledby the electric potential.

4


the flight phase. Two laboratories are col-laborating on the project in St. Gallen: Thetechnical know-how for the electro-spin-ning process originates from the lab for“Protection and Physiology”, the knowl-edge of biodynamics is provided by the“Biomaterials” lab.

For medical applications it is importantnot to use noxious solvents, since the endproduct must not contain any toxic materialswhatsoever. Lavielle and his colleagues AnaMaria Popa and Matthijs de Geus thereforedecided to use the polylactide bio-plastic ina mixture of acetic and formic acid. Thebody copes well with both acids if tracesthereof were to adhere to the finished tex-tile. Another advantage is that the acidsslowly dissolve the polylactide, meaningthat the molecular weight and the viscosityof the solution can be controlled in an ele-gant way, thus regulating the thickness ofthe fibres. The researchers have already suc-ceeded in spinning polylactide to create fibreswith the required diameter. Now, they are onto the next step: incorporating drugs in thepolymer.

Simulated human sweatOnce that is accomplished the teamwants to start trials in order to reg-ulate the drugs’ release rate. Twoparameters are crucial for doingthis: the drug concentration in

the fibre and the thickness of the fibres pro-duced by electro-spinning. The thinner thefibre, the bigger the active area of the fabricand the faster the decomposition of thepolylactide.

Animal testing is not required at thisstage. Instead, the samples manufacturedat Empa will be dissolved in special fluidsthat simulate human blood serum or hu-man sweat. The results could actually bethe basis for the multifunctional wounddressing of the future. This would meanthat anti-inflammatory drugs and anal-gesics would no longer have to be admin-istered systemically and thus flush the en-tire body – they would be applied exactlywhere they are needed: directly onto thewound. //

http://youtu.be/NnaoT9bCaLoFor smartphone users: scan the QR code(e.g with the “scanlife” app)

Video:Elektrospinningin slow motion

4The result of electro-spinning is a small cot-ton ball made ofthreads intermeshedwith each other.

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Novel implant screws for

improved bone healing

Medical textiles such as

analgesic patches made from

biodegradable polymers

Safety research

for nano-materials and

-surfaces

Design of biocompatible

implant surfaces that promote

cell and tissue growth

Cooling apparel

for MS patients

Textile sensors

for health monitoring

Medical Technology– made by Empa

Protective clothing for fire

fighters, the police force

and recreational sports

Artificial heart valves and

blood vessels based on textiles

Spinal disk implants made

from nano-fibrillated

cellulose

High-strength alloys and

surface coatings for

artificial joints

Artificial muscles for

active walking aids

Incontinence pants for patients

with urinary incontinence

Corrosion research on implants

and artificial joints


“Empa's passion is tounderstand a problem:ours is to solve it”

Robert Frigg, CTO of implant manufacturer Synthes, is aware of thepotential of collaborating with Empa – but he is also consciousthat friction can occur in projects such as this. He already helped severalcooperative research projects to mature into marketable products.

INTERVIEW: Rainer Klose / PICTURES: Synthes, Empa


>>

EN: Mr. Frigg, how did the collaboration betweenSynthes and Empa start?

Frigg: The first really large project began in 2006 withinitial discussions and then started up in 2007. Prior tothis, we had already placed various testing orders withEmpa; collaboration up to this point in time had thereforebeen restricted to defined, clearly outlined orders.

What was the first big project about?We wanted to develop an intervertebral disk in

which metal interacted with metal. We asked Empaabout it.

What exactly were you looking for from Empa –and what did you find? Doesn't Synthes have itsown laboratories?

It is important for a company to obtain expert-ise that is not available in-house. A develop-

ment group from industry is specialised incertain things such as metrology, de-

sign issues and matters concerningmaterial fatigue. Then there arethings that go beyond this, whichare new areas. A replacementjoint was new to us at that time.We developed the knowledgeabout the structure and kine-matics of the required compo-nent together with Empa. It wasparticularly important to have

an extremely hard layer madefrom so-called “diamond-like car-

bon” (DLC), with which we wantedas coating on the surface in order to

reduce friction. We started a CTI projectin order to do this, and did the research to-

gether with Empa. Two post-doctoral re-searchers worked on the project for us.

Was this a major step for Synthes? It really is a completely new level. Prior to this we

just placed individual orders. We say: I want that fromyou, how much does it cost, how long will it take? Nowit is about learning together and achieving a commonpurpose: We want to apply this super-hard coating toour own products.

What is the situation regarding confidentiality andprotection of intellectual rights? With such animportant project, are you not worried that com-petitors can look behind the curtain in the Empalaboratories and take away results?

We are not worried about visitors entering the lab-oratory. There are special investigations under way thata layman is unlikely to understand. However, we mustmake use of our expertise for a project. And this specificknowledge turns a screw, which basically anyone canmanufacture, into a high-value medical engineeringproduct. We have known for years exactly how thescrew is used, what the risks are and what is important.We pass on all of this when we enter into a partnership.

How can you protect yourself if Empa gains all ofthis knowledge? For example, what happens ifthe project has finished and one year later acompetitor would like to start a similar projecttogether with Empa? Is Empa allowed to pass onthe know-how?

Can you prevent that? No. Ultimately you cannot.It it a case of protecting yourself using certain clauseswhen the agreement is signed – and by making a quickdecision whenever progress is made: Do we want toprotect this with a patent, or should we give the resultto the public? But of course, the transfer of knowledgeis not a one-way street: We also benefit from knowledgethat Empa has obtained in their previous cooperations.Ultimately it is give and take, about fifty-fifty. Our phi-losophy has proven itself well so far: We check exactlywhat can be patented from the project, and registerpatents immediately.

Is it worth the risk? After all, you have your ownresearch department. Can't you do the researchyourself and maintain complete secrecy?

Yes, at Synthes we have about 700 employees in thedevelopment department, of which about 400 are engi-neers, physicists and chemists. However, we do nothave the laboratories for such special coating problems,and do not wish to set up ones. In cases like this weachieve our goal more quickly with external experts.

Have you also come across new ideas at Empathat may be useful to your company?

Of course! During a presentation we were shown aprototype from “compliant systems”, operating forcepsmade from flexible materials with no joints whatsoever.This was extremely interesting to us from a production-related point of view. Such an instrument would be ex-tremely easy to clean, and could be made from plasticif necessary. This prototype certainly gave us some newimpetus when thinking about future products.

Did anything come of it?Unfortunately, this idea did not make it to readiness

for market. In this case we tried out a few things, butplastic forceps may be too big of a jump – and not use-ful enough in medical practice. Occasionally, the col-laboration with Empa changes at a certain point. Thisis because the researcher is only interested in a projecthe can reveal (i.e. publish it). However, when furtherdevelopment is necessary to achieve readiness for se-ries production, this kind of work has to take place be-hind closed doors. At that stage the project is no longerof interest for scientific publications. Of course, we un-derstand this, and this part is not Empa's job at all.

In other words, as a company, you reach a pointwhere you have to take over and continue devel-opment of the project yourself?

Yes, and that is also understandable. As an indus-trial company you have to understand the mentality ofthe researchers: They are interested in understanding aproblem. Our job is to solve it. This is the difference.


Are products developed together with Empa al-ready on the market?

Our DLS is a good example, our Dynamic LockingScrew. This special screw flexibly connects the bone tothe splint. It can therefore move, which accelerates thehealing process of the bone. The screw must be madefrom a high-strength metal alloy, which we developedand validated together with Empa. The screw is on themarket since January 2012.

Mr. Frigg, thank you for the interview.

DePuy Synthes

Synthes is a Swiss/US medical engineering company with about 10000 employees worldwide. It man-ufactures, produces and markets instruments, implants and bio-materials for the surgical treatment ofbone fractures and for correcting and reconstructing the human skeleton and its soft tissues. In thespring of 2012 the company was taken over by US concern Johnson & Johnson and merged with theDePuy subsidiary. It now bears the name “DePuy Synthes Companies of Johnson & Johnson” and claimsto be the world's biggest manufacturer of orthopaedic and neurological tools for medicine.

>>

What's going on at the moment?Are you currently working on a projectwith Empa?

We were recently granted a CTI projectdealing with colour coating on stainless steelscrews. Coloured marking is a major topic insurgery – it makes it easier for the surgeonto find the right screw for a certain compo-nent immediately: He only has to tightenthe blue screw with the blue screwdriver,

and everything is OK. This has long sincebeen the case with titanium screws, but it isnot as easy as that with stainless steel.

Why?With titanium, and also aluminium, thin

interference coatings can be created on thesurface by anodising, which makes themshine in a certain colour. This is not possiblewith stainless steel. With the help of our em-ployees who are at Empa we developed a suit-able coating. This has now been validatedand has already gone into production.

Are you talking about employees who areworking at the Empa campus?How did this model come into existence?

The idea emerged as we recognised that a postdoc-torate student often has insufficient time to achieve thegoal at one go. Usually the scientist comes far enoughto have understood the problem. But as his contractruns out and he goes away, he cannot solve it. This iswhy we leave the scientists to Empa when their contractthere runs out, and take them onto our salary budget.We therefore have an expert available who knows theproject and its surrounding circumstances – and we alsonow have time to seek the solution carefully.

For how long do you use this system now?We introduced it in 2010. It has proven itself, be-

cause the researchers also took the opportunity to ac-company their “baby” and guide the project to success.This is not just a one-way street – Empa researchersduring the project also meet with our specialists, andnetwork internationally with the developer scene. Theresearcher therefore also learns something extra andbenefits from our partnership.

Synthes CTO Robert Frigg (center) cultivates a particularly close researchcollaboration with Empa. His team supports him in this. Left: Cyril Voisard,the contact for Synthes researchers at Empa, right: Peter Brunner, Head ofInnovation at Synthes.


When you think about stainless steel, of cobalt/chromi-um/molybdenum, of titanium/vanadium – images im-mediately spring to mind of shiny tools that are expen-

sive, tough and durable. They are every mechanic's dream. Some-thing that is good enough for tools in a garage or as a componentin an engine should easily withstand the conditions in the humanbody: mild salt solutions with a few proteins at a consistent 37degrees C. Nothing is glowing with heat or gleaming with frost.And humans have far less horsepower than a sports car, meaningthat the mechanical demands are also within reason.

“Wrong,” says Patrik Schmutz. The Empa specialist for cor-rosion research has seen many defective artificial joints that hadto be removed. He has also seen screws that have been eatenaway, corroded metal parts and cracked splints. Together withpartners from industry he is investigating how this can happen –and how better implants can be designed in the future.

“Gap corrosion is one main culprit,” says Schmutz. “Notmuch happens on the surface of the implants; but the conditionsin the narrow gaps between a screw and the plate that it is holdingin place are dramatic.” The pH value there frequently drops to 0,and the extremely acidic environment eats away at even the hard-est metals. “We then face two problems,” says Schmutz, “the im-plant loses stability and metal ions, i.e. toxic materials, travelthrough the body.”

The Empa researchers figured out the phenomenon using physical andelectro-chemical methods. These include mechanical tests such as small con-tainers containing synthetic body fluid, in which metal test samples are movedand subjected to load for months on end. The corrosion damage is then eval-uated under an electron microscope. Using a unique method the Empa expertsfinally investigate suspected cases of gap corrosion: they use micrometre-thinglass capillaries to examine the electrochemical processes in minute volumes.In the end, the individual pieces of the puzzle can be put together to producean overall picture of the corrosion process.

But how can the problem be solved? “On the one hand, we have to developnew, corrosion-resistant alloys,” explains Schmutz. The geometry is also deci-sive. “We must attempt to avoid fine gaps wherever possible and constructcomponents that do not move against each other.” The “Dynamic LockingScrew” that was developed in collaboration with Synthes (see interview onpage 18) is an example of such implant technology of the next generation. Butuntil the problem has been solved completely we better keep a watchful eyeon everything that is put into the human body. //

Corrosion in the human bodyEmpa investigates why even expensive alloys in implantscan fail. The goal: implants that are better designed andlast for longer.

TEXT: Rainer Klose / PICTURES: Empa

10 µm

gap corrosion

metal plate

bone

1Crevice corrosion arises at constricted areas be-tween metal parts where pH drops dramatically.The acid then corrodes the alloy.

2Corrosion on a titanium implant in an electron mi-croscope. The material failure starts at the grainboundaries.

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22 // Knowledge and technology transfer

The bridge whisperer Sometimes bridges just go berserk. The deck and the cables vibrate heavily,and the bridge has to be closed. This is a case for Felix Weber. He knowshow to get these resonance problems under control using hydraulicdampers, counterweights and electronic controllers and make the shakingstructures see reason.

TEXT: Rainer Klose / PICTURES, ILLUSTRATIONS: Empa

1In 1940, the TacomaNarrows Bridge in Wash-ington State in theUS was torn apart due touncontrolled oscillations.

2Felix Weber on hisbridge model in Empa’sconstruction hall. Withit, researchers can gen-erate specific resonantoscillations – and try outvarious solutions.

Every bridge is unique. Made to meas-ure at their location, designed by ar-chitects who want to deliver some-

thing elegant. The bridge must be filigreerather than lumbering, airy rather thanbulky, a real jewel. However: Sometimes itdoesn't work. The most infamous exampleof an extremely slender bridge with a widespan is (or better: was) the “Tacoma Nar-rows Bridge” in Washington state in the US.Known as “Galloping Gertie” by its fans be-cause of its see-sawing road surface, it col-lapsed in November 1940 just four monthsafter opening. The deck cracked in a stormand fell into the water, together with twoabandoned cars. The wreckage is still on thebottom of the Tacoma Narrows, where it hasbeen placed under a preservation order.

Such a drastic resonance phenomenonhas never occurred since, but vibration isstill a problem as far as bridges are con-cerned. In June it affected the “MillenniumBridge” designed by star architect NormanFoster, a footbridge over the Thames in Lon-don – on its very opening day! Its load-bear-ing capacity was designed for 5000 people,but less than 200 people were enough tostart a considerable amount of vibration. In-vestigations revealed that the vibration thatoccurred made people walk in lockstep,

which made the vibration even worse. Twodays after opening, the “Millennium Bridge”was shut and passive mass dampers were installed: Steel weights topping 20 tons tocounter the horizontal vibration and even 50 tons to counter the horizontal vibration –exactly adjusted to the pedestrian-induced vi-bration frequency that had made the bridgeso dangerous.

When the wind whistles throughthe cablesHowever, what can be done if the trigger can-not be calculated so precisely beforehand?What if multiple factors play a part? Duringheavy winter storms in March 2005, the sup-port cables of the Franjo Tudjman Bridge inCroatia, which spans an estuary north ofDubrovnik, started to vibrate. The dampsnow had stuck to the cables and given thema kind of “wing profile”, which made it easierfor the wind to excite vibration. Felix Weber,a specialist for active damping in Empa’s“Structural Engineering” laboratory, knewexactly what to do: just install his new elec-tronically controlled adaptive cable dampingsystem developed together with Munich-based Maurer Söhne. Sensors record the vi-bration of each cable and relay the signal to acomputer, which then actuates the magneto-

1

2

3Oscillation dampers(on the right) were alsoplaced on the supportcables of the Sutongbridge in China withassistance from Empa.

Knowledge and technology transfer // 23

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rheological dampers (MR dampers) individu-ally. In this way, the system manages to sup-press vibration in the best possible way, inde-pendently of frequency and amplitude.

Thus far, the cables of the Franjo Tudj-man Bridge have maintained their stabilityfor six years. Weber then turned his hand tothe largest cable-stayed bridge in the worldat that time: the Sutong Bridge in China,which crosses the Yangtse with a free spanof 1080 metres. Weber helped the Chinese tostabilise the cables, which are up to 540 me-tres long, with 48 MR dampers and 224 pas-sive oil dampers. The adaptive cable damp-ing system was installed during the con-struction of the bridge and has proven itselfto this very day. Currently, the cables of theRussky Bridge crossing the sea betweenVladivistok and “Russky Island” with theworld's longest free span of 1104 metres,which are up to 580 m in length, are beingequipped with controlled MR dampers.

Wobbly girder bridgeMeanwhile, Felix Weber has new targets;instead of “only” providing cables withadaptive damping, he now wants to take onentire bridges. Such an opportunity arose inVolgograd. Again, a bridge had unexpected-ly started to vibrate. Only this time it wasn’ta cable-stayed bridge but a girder bridge –the longest in Europe at 7.1 kilometres. Ittook 13 years to build the road bridge overthe Volga, which opened in 2009. In May2010 winds were so strong that the deck ofthe bridge started to vibrate dangerously atthree frequencies – 0.45, 0.57 and 0.68Hertz. The constructors decided to use We-ber's brand new damping concept forbridge deck vibrations, a MR-controlledmass damper.

Weber, a mechanical engineer by train-ing, can fall back on a unique test set-up atEmpa in order to test his latest developmentsin practice: In one of the halls at the Empacampus in Dübendorf there is a 20 metre-long cable-stayed bridge that is in the dry allyear round. He had already developed hiscable damping system on this lab bridge.The elegant thing about Weber's innovativesolution for vibrating building structures:Whereas passive mass dampers such as theones on the Millennium Bridge in Londonare “tuned” to a pre-calculated frequency, anMR-controlled mass damper adapts to anymeasured vibration frequency – whichmakes the damping significantly more effi-cient. Or to put it another way: A light adap-

tive mass damper yields the sameperformance as a considerablyheavier passive damper. Themass damper of the 1.7 ton Empalab bridge weighs just 27 kilo-grams and is attached to thebridge via springs.

Variable damping for any frequencyThe 7.1 kilometre, three-laneVolgograd road bridge requiresdampers that are somewhat big-ger, of course. Weber and Maurer decidedto damp the three vibration frequencieswith three 21-ton spring mass systems thatwere adjusted to these frequencies. In or-der to install the mass dampers in the slim-line bridge deck, they first had to be“chopped up” into four pieces, each weigh-ing more than 5 tons. The system has beenoperating reliably since last autumn. Byway of comparison: Twelve years earliermore than 70 tons were required to sta-bilise the Millennium Bridge, which wasonly 370 metres in length. The adaptivemass damper from Empa, therefore, hassome “weighty” advantages. Empa partnerMaurer Söhne now also markets the newconcept for one- and two-dimensional vi-bration damping on skyscrapers, observa-tion towers and airport towers. //

controlled positive ornegative stiffness for

frequency tuning

mass

main structure modal mass

pass

ive

sprin

g

MR

dam

per

controlled frictionfor damping tuning

1Diagram of a controlled mass damper

2Felix Weber shows how an MR damperhelps him come to grips with oscillationson his bridge model. Middle: an adap-tive mass damper on the bridge model.Below: Felix Weber tests the originalweights for the Wolograd bridge prior toassembly.

http://youtu.be/ILo_-u2EqJgFor smartphone users: scan the QR code(e.g with the “scanlife” app)

Video:When bridgesgo beserk

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inhabitant

rivers

paint withnanoparticles

craftsman

exterior coating interior coating

soil

ground water

airair

water

farmer

rain, wind, sun

consumerinhabitant

rain, wind, sunwind sun


In the EU-funded “Nanohouse” project,the opportunities and risks of these nano-additives are examined from an ecological

and toxicological point of view. Several Empateams are investigating whether and hownano-materials are released from façade coat-ings during the entire product lifecycle, andwhat their possible effects on the environ-ment and human beings might be.

Rather unique about this project: it notonly looks at newly manufactured nano-materials but also at coatings that were“aged” and exposed to various influences.For this purpose, new methods had to bedeveloped in different areas.

Blessing and curse of oxidationAs well as nano-silver for interior façades,nano-titanium dioxide and nano-silica ma-terials for exterior and interior coatings

were examined. Nanoparticles made fromtitanium dioxide can be activated by sun-light to chemically decompose dirt parti-cles and other substances (a processknown as photo-catalysis). This meansthat the dirt could be simply washed off byrain, making the paint “self-cleaning”, soto speak, and therefore more durable.

However, this could also cause organicbinding agents in the paint to oxidise. Empais investigating how the paint actually reactsby artificially weathering façades. The re-searchers simulate the effects of the environ-ment and various weather conditions by il-luminating the façades with artificial sun-light, for example. The paint ages consider-ably faster by means of intensive artificialweathering, thus showing the researcherswhat happens if the rain washes off not justthe dirt but also the aging paint.

Nanoparticles in paint:a good idea?House façades have to withstand quite a bit of stress: UV radiation,temperature fluctuations, rain and abrasion. A new generationof nano-additives could counteract these effects better than everbefore. But is it risky to mix them into the façade paint?

TEXT: Rainer Klose / ILLUSTRATION: André Niederer

Biological effects on humans and animalsFive Empa laboratories are involved in the“Nanohouse” project, which will examinethe use of nanoparticles in paint over athree and a half year period. Lifecycleanalyses of these nano-paints, the func-tionality and longevity thereof and the re-lease of different nanoparticles and theirpotential biological effects on humans andthe environment are examined. BesidesEmpa, eight partners are involved, four ofwhich are from industry. At just about half-time, the project is still in progress.

Once finished, the scientists hope thatthey will have established the basics for a newgeneration of wall paint: Coatings that areharmless to people and the environment inthe long-run. Because paint that lasts longerreduces paint usage and therefore also con-tributes to protecting the environment. //

Nanoparticles in a house. Where do they finally go?


It's all go at cable manufacturer Huber+Suhner. Every processin the factory is in place – from the delivery of the copper wireto the finished reel of cable. This is also necessary, because

high-tech cables from Pfäffikon in Zurich have to withstand quitea few things, they must continue to function in extreme cases suchas when being used as jumper cable in trains. The prducts holdup to their promise thanks to a unique treatment using electronbeam polymerisation: the plastic is blasted with electrons andmade “unmeltable”. This provides the cable with a sheath thatwithstands even the highest temperatures.

Costs are kept down in the factory using an on-demand sys-tem, low storage costs and a high degree of machine utilisation.In spite of this, Peter Schmollinger, process technology managerat Huber+Suhner, is continuously thinking about individualstages of the process. On the one hand because it is his job to im-prove existing processes and develop new ones, but also becausethe company puts value on examining the ecological effects oftheir activities. “Companies know their material and wage costs.But what costs do the hidden energy consumers generate?” asksSchmollinger. He wants to to know the facts: Does it make eco-logical sense to keep the plastic in the extruder that puts thesheath around the cable warm all the time? Or would it be better

In the CTI-funded research project “EcoFactory”, Empa researchersare working with industrial partners, economists from the ETH Zurichand computer scientists from the HTW Berlin to develop software,with which companies can determine the most energy savingprocesses for their manufacturing facilities.

TEXT: Martina Peter / PICTURES: Empa / ILLUSTRATION: André Niederer

An eco-friendly factory

unwinder conductor-heating extruder cooling drying 1


from an energy point of view to allow the polymer compound tocool down during production breaks and heat it up again when itis needed?

Individual steps in the process would also have to be organ-ised differently from an ecological aspect wherever possible,thinks the precision engineer. In Pfäffikon the cable runs througha water bath to cool after the sheath has been extruded. A high-pressure dryer dries it a a few metres further on. Now, does thismake sense energywise, or could the cooling and drying processbe organised in a better way that would save energy? Are thereany alternative drying methods? Can these be operated in a finan-cially acceptable way that allows the same amount of cable to beproduced within the same time? Because Schmollinger is sure ofone thing: “No company wants a green factory that doesn't earnanything”.

“EcoFactory” combines financial and ecological perspectivesAs a process engineer he has a gut feeling for the direction, inwhich things must go. However, by means of the joint “EcoFac-tory” project together with Empa and the ETH Zurich he hopes toobtain feedback that is more objective. The core of the project isa software that simulates how processes should be set up and co-

1Functional diagram of acable factory.

2A worker discusses a ma-terial sample from thecable factory withprocess engineer PeterSchmollinger.

ordinated in an ideal way, so that the company can reach both fi-nancial and ecological targets. And precisely this “not only – butalso” between market and environment is the new thing about“EcoFactory”; the program does not just model economic vari-ables such as utilisation, timing, idle times (i.e. overall cost-effec-tiveness), but models, evaluates and optimises processes with re-gard to sustainability. Anyone who would like to organiseprocesses in a factory more ecologically is quickly confronted withlifecycle assessments (LCAs), dealing with resources, CO2 emis-sions and disposal of waste products – all of which are extremelycomplex issues.

Empa’s lifecycle assessment know-howThis is exactly where Empa comes in. Empa researchers con-tribute their expert LCA knowledge and the “ecoinvent” database(see box). They have many years of experience with systematicanalysis of the environmental effects of products during theiroverall lifecycle. “Actually, we look at things in a similar way tothe economists,” says Empa researcher and LCA expert RainerZah, “we are also always looking at the entire value chain.” Ac-cording to Zah, many manufacturing companies would have re-alised that they should integrate the ecological perspectives into

quality-check 1 crosslinking withelectron-beam

printing quality-check 2 winder shipping

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2


process management, which to date has been financially drivenin most cases. But where do you start? For example, if you wishto purchase a new, more efficient machine, you have to knowwhether you can save money by using less energy and smallerquantities of auxiliary materials and adhere to the legal limits.

The EcoFactory software will help you do this in future. If thefinancial model is directly coupled to the methods and data forLCA, companies can determine which machines run for how longin a manufacturing process and which materials they require.They can also simulate emissions, reveal resource consumptionand record waste products. Because the ecological dimension isby no means limited to energy, says Zah.

By the end of 2013 when the project will be finished, the toolshould be developed to a stage where it can be used commercially.Large companies that have their own environmental departmentcan use the tool themselves, and SMEs will be in a better positionto approach energy agencies with specific questions. Now, at“half-time”, ETH and Empa scientists often visit their industrialpartners. “These are all companies that are already ahead in termsof protecting the environment, but want to take it even further,”declares Zah. “This makes the work extremely interesting.”

Collecting and analysing dataAs one of the industrial partners, Peter Schmollinger from Huber+Suh-ner is currently making “his” processes available for recording andanalysis. At the end of May the ETH team recorded a full week of pro-duction, during which about 3500 m of high-tech cable was manufac-tured. They recorded each production step at one-second intervals:during extrusion, water cooling and electron beam polymerisation.This provided them with key figures for energy consumption, emis-sions, water usage and material flows.

Once the pieces of the puzzle have been put together, newprocesses, in which the work operations take place in a different order,can be simulated and the best cost-effectiveness can be determined.More than a dozen similar systems are available at Huber+Suhner,to which the optimisation could be transferred. And of course, theknowledge that is gained can also be used for new manufacturing fa-cilities. Even if these are extremely specialised – such as the new elec-tron beam polymerisation system next to the factory building, wherethe walls of the concrete bunker are several metres thick and the ca-bles are processed in a high-vacuum. //

>>

Engineer Peter Schmollinger scoures the factory for energy“leaks”. Top: the unwinder at the start of cable manufacturing.Below: the cooling basin, through which the cable runs after theplastic insulation has been applied.

Who is developing “EcoFactory”?

“EcoFactory” is software for companies that do not just want to optimise their man-ufacturing processes financially but also ecologically. It is currently being devel-oped within the scope of a project supported by the Commission for Technologyand Innovation (CTI); besides Empa, other partners in the CTI project are the ETHZurich, the Hochschule für Technik und Wirtschaft HTW Berlin (Berlin University ofApplied Sciences) and industrial partners Taracell Switzerland, Huber+Suhner AG,Knecht & Müller AG, Chocolat Frey AG, Effizienzagentur Schweiz AG (EfficiencyAgency Switzerland AG), the SWISSMEM industry association and the R&D consor-tium “Sustainable Engineering Network Switzerland” (SEN).


Awork of art, the “Solar Window”was designed and developed byartist Daniel Imboden and Thomas

Geiger, a researcher in Empa’s “FunctionalPolymers” laboratory. Nine transparent,multi-coloured solar cells rotate slowly in aframe around their own axis. The silentmovement and the coloured shadows the in-stallation casts on its surroundings exudecalm, and make you think about the powerof the sun, thus perfectly exemplifying thesubject of the exhibition: “The Sun Moves”.The exhibition in the Swiss Museum ofTransport puts the focus on sustainable mo-bility. Means of transport that obtain theirpower from solar energy are exhibited. Be-sides a solar-powered car (which sponta-neously comes to mind on this subject), sail-ing boats and gliders are also featured. Be-cause after all, thermals and wind poweralso originate from the sun.

Special solar cells for diffuse light Empa researcher Thomas Geiger and Swisscompany Solaronix decided that the “SolarWindow” should be equipped with a specialtype of solar panel. The so-called Grätzel

cells, named after their inventor MichaelGrätzel, researcher at ETH Lausanne, cap-ture sunlight using various organic dyes in-stead of silicon. As well as having a morefriendly, colourful look, this also has otheradvantages: The cells are transparent andalso function in diffuse light. The play ofcolours therefore does not just rotate in theglistening sun, but also in the partial shadeof the exhibition between wall charts andwandering visitors. Each cell provides thepower for its own movement.

Three colours – three stagesof developmentThe three colours of the exhibit are also sym-bolic of the development of the Grätzel cell,which was first described and patented 20years ago. The dark red elements functionwith the original dye, a ruthenium complex,which Grätzel used in his first cells. Theturquoise-coloured cells use chemistry thathas been developed in the Empa laboratory,based on squarine dyes. The orange-colouredcells are a new development by Solaronix, acompany that has been commercially devel-oping the technology since 1993. //

“The Sun Moves”exhibition at the SwissMuseum of Transport inLucerne. Empa researcherThomas Geiger explainsto a visitor how therotating, coloured solarcells operate.

Moved by sunlightThanks to Empa, the current exhibition at the Swiss Museum of Transport inLucerne entitled “The Sun Moves” has got a new attraction. A display cabinetfull of colourful, rotating solar cells demonstrates the power of sunlight, andshould give visitors food for thought.

TEXT Rainer Klose / PICTURES: Empa, Swiss Museum of Transport

The “The Sun Moves” exhibition is open dailyfrom 10 am until 6 pm and runs until 21st October in the inner courtyard of the SwissMuseum of Transport, Lidostrasse 5, 6006Lucerne, Switzerland. More information canbe found at www.verkehrshaus.ch

http://youtu.be/UkLJKqw7zrsFor smartphone users: scan the QR code(e.g with the “scanlife” app)

Video:Solar art atSwiss Museumof Transport

30 // Science dialogue

Anniversary at the “Top of Europe”Measuring airborne pollutants at the Sphinx observatory on Jungfraujoch since 1973, Empa has been instrumental in determining air quality,not just in the Alps but throughout Europe. This is because everything that pops up at Jungfraujoch and is detected there has to come fromsomewhere or other. The route the pollutants have taken – and therefore their origin – is calculated with weather models from MeteoSchweiz. The series of measurements that Empa started in 1973 is among the longest in Europe, and is invaluable to researchers all overthe world.

The research station on Jungfraujoch is, however, considerably older: Theoutpost at 3571 metres altitude was opened in 1931 – initially as an astronomicalobservatory and a laboratory for altitude sickness. The Sphinx observatory,named after the peak on top of which it is perched, followed in 1937 – i.e. exactly75 years ago. Nowadays more than two dozen international research groups workat the centre each year. 20 automatic measuring instruments are constantly inoperation, monitoring weather, radiation and atmospheric data.

On the occasion of the 100th anniversary of the Jungfraujoch railway, whichbegan operation in 1912, the scientific work is now the subject of a permanentexhibition with display boards and video documentations. The research stationon Jungfraujoch is the highest research station in the world that can be reachedby public transport.

www.empa.ch/EN37-2For smartphone users: scan the QR code(e.g with the “scanlife” app)

Video:Research atJungfraujoch

Science dialogue // 31

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Young entrepreneur awardfor Empa start-upThe winner of the first “SwissParks.ch Award” and therefore the “Start-up of the Year2012” is QualySense AG, an Empa start-up. The prize worth 10,000 Swiss Francs wasawarded by the Swiss Business Group and Assoii-Suisse (Associazione degli Impren-ditori Italiani in Svizzera) in Lugano on 22 May. The intentionof this award from SwissParks.ch – an association of Swisstechnology parks and business incubators established in theyear 2000 – is to recognise fledgling companies, which havemarket potential and exemplify Switzerland as a place for high-tech, research and development with their innovative prod-ucts.

The winner, QualySense AG, develops high-end solutions forsorting grain, seeds and beans. Their product, the QSorter, checksthe basic biochemical and/or geometric properties of each individ-ual grain of the product that is being inspected, and sorts it accord-ing to customer-specific criteria. The customer, therefore, achievescontinuous quality control, process optimisation and and risk min-imisation. QualySense was founded in 2010 by Francesco Dell'En-dice and resides in the Glatec technology centre on the Empa cam-pus in Dübendorf.

From left to right: representative of Winterthur Instruments GmbH, Jean-Philippe Lallement (Chairman of SwissParks.ch), Paolo D’Alcini (COO ofQualySense), Nicola Rohrseitz (CEO of ViSSee).

Events14. August 2012Neue Antriebstechnologien:Von der Forschung zur MarkteinführungInfo: www.e-mobile.chEmpa, Dübendorf

4. September 2012Hightechnähte aus der Forschung –Laserschweissen von Textilien und MembranenEmpa, St.Gallen

25. Oktober 2012Tage der Technik 2012: Die Stadt der Zukunft –die Zukunft der StadtInfo: www.swissengineering.chEmpa, Dübendorf

12. November 2012MedTech Day 2012 –Von der Idee zum MedTech-ProduktEmpa, Dübendorf

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