ZHAW ICP Research Report 2012

Research Report 2012

Zurich Universities of

Applied Sciences and Arts www.engineering.zhaw.ch Research & Development

r d

Beispiel von Verschiebungen einer konischen Schale mitDurchschlagsverhalten und gewölbten Lösungen. Die koni-sche Schale deformiert sich und nähert sich nach einer ge-wissen Zeit einer instabilen Region, in der die Schale durch-schlagen kann. Erhöht sich die Verschiebung weiter, kommenwir zu einem Bifurkationspunkt, an dem gewölbte Deformatio-nen auftreten.

Example of a conical shell displacements with snap-throughand warp solutions. The conical shell starts to deform inwardand after a while it approaches an unstable snap-through re-gion, by further increasing the displacement, we arrive at abifurcation point where warp deformations show up.

Contents

Vorwort 3

Preface 4

1 Modeling and More 51.1 Simulation von Personenströmen als Kontinuum bei Grossanlässen und dichtem

Personenverkehr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.2 Materialcharakterisierung in der Lebensmitteltechnologie mittels Ultraschall-Verfahren 61.3 Neuartig optimierte Kühlprozesse zur nachhaltigen Herstellung von gefüllten Schoko-

ladenprodukten mit verbesserter Qualität . . . . . . . . . . . . . . . . . . . . . . . . 71.4 Modeling the Cooling Curve of Soy Oil . . . . . . . . . . . . . . . . . . . . . . . . . . 81.5 Virtual Layout for Continuous Casting of Steel . . . . . . . . . . . . . . . . . . . . . . 91.6 Pore Clogging During a Long-Term Experiment with Bentonite Buffer Material: Pore-

Space Percolation and Prediction of Air Permeability . . . . . . . . . . . . . . . . . . 101.7 A New Developped Method for the Optimization of the Adhesion Strength of Ceramic

and Metallic Coatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121.8 Automatic Ice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141.9 Diagnostic Device for the Early-Stage Detection of Skin Cancer . . . . . . . . . . . . 151.10 Produktionskontrolle von Pulverbeschichtungen mittels thermischer Schichtprüfung . 16

2 Fuel cells 172.1 Optimierung eines SOFC Brennstoffzellenmoduls . . . . . . . . . . . . . . . . . . . . 172.2 Leckagenanalyse im Hexis Brennstoffzellensystem . . . . . . . . . . . . . . . . . . . 182.3 Topological Analysis and FE-Simulation for the Study of Microstructure Degradation

in Solid Oxide Fuel Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192.4 Oxide Scale on Interconnectors after 40’000 Hours Fuel Cell Operation . . . . . . . 202.5 Relationships between 3D Topology and Reaction Kinetics in SOFC Electrodes . . . 212.6 Thin-Membranes Design in Micro-Solid Oxide Fuel Cell . . . . . . . . . . . . . . . . 222.7 Belenos Fuel Cell Stack: Simulation and Freezing . . . . . . . . . . . . . . . . . . . 23

3 Energy Systems 253.1 Exploring and Improving Durability of Thin Film Solar Cells . . . . . . . . . . . . . . 253.2 Simulation of Hydrogen Production with a Photoelectrochemical Solar Cell . . . . . 263.3 Integration of High Temperature Electric Converter for Electricity Generation in a

Solide Oxide Fuel System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283.4 Thermofluiddynamische Modellierung von Biomassevergasung . . . . . . . . . . . . 29

4 Organic Electronics 304.1 Light Outcoupling from Organic Light-Emitting Diodes . . . . . . . . . . . . . . . . . 304.2 From Atoms to Large-Area OLEDs -the IM3OLED Project . . . . . . . . . . . . . . . 314.3 Erweiterung der Laborinfrastruktur zur Herstellung von Organischen Leuchtdioden

am ICP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

1

Research Report 2012 Institute of Computational Physics

Appendix 33A.1 Student Projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33A.2 Scientific Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34A.3 Book Chapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35A.4 News Articles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35A.5 Exhibitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35A.6 Conferences and Workshops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35A.7 Prizes and Awards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37A.8 Teaching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38A.9 ICP-Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40A.10 Spin-off Companies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41A.11 Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

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Vorwort

Was haben Brennstoff- oder Solarzellen mit Schokolade gemeinsam ?Alterungsprozesse spielen bei der Erforschung neuer funktionaler Materialien eine zentrale Rolle.Wenn es zum Beispiel darum geht, Brennstoffe, Wärme oder Sonnenlicht direkt in elektrischeEnergie umzuwandeln, führen unerwünschte Alterungsprozesse häufig zu einer starken Abnahmeder Effizienz. Typischerweise zeigen sich diese Alterungsprozesse in Veränderungen der mikro-skopischen Beschaffenheit der Materialien, der sogenannten Mikrostruktur.Experimentell lassen sich sowohl Alterungsprozesse als auch die Leistungsfähigkeit von Mate-rialien gut abbilden. Mit der Hilfe von Rasterelektronen- oder Focused-Ion-Beam-Mikroskopenkönnen 2D- oder 3D-Mikrostrukturaufnahmen erstellt werden. Und die Leistungsfähigkeit vielerMaterialien lässt sich über Impedanzspektrokopie ermitteln. Gilt es jedoch, quantitative Verän-derungen in der Mikrostruktur mit der daraus resultierenden Verminderung der Leistungsfähigkeitzu korrelieren, stösst die experimentelle Forschung an ihre Grenzen.Hier kommen Computermodelle ins Spiel. Sie bilden die im Material ablaufenden Prozesse überphysikalische Modelle ab. Dabei werden Mikrostrukturaufnahmen als Input verwendet, um da-raus die Performance des Materials vorherzusagen. So helfen Modelle, Alterungsprozesse besserzu verstehen, Herstellungsprozesse zu optimieren und negative Materialeigenschaften von vorn-herein zu vermeiden. Das erklärt auch, was eine Brennstoff- oder Solarzelle mit Schokoladegemeinsam hat: In all diesen Materialien laufen Alterungsprozesse ab, die von der Mikrostrukturabhängen und über Computermodelle simuliert werden können.Wie breit gefächert die Wissenschaftler des ICP forschen, erfahren Sie anhand des vorliegendenJahresberichts 2012.Auch in diesem Jahr möchte ich an dieser Stelle allen Mitarbeitern unseres Instituts für ihr grossesEngagement, ihre Begeisterungsfähigkeit und die tolle gegenseitige Unterstützung ganz herzlichdanken.

Thomas HockerInstitutsleiter

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Preface

What do fuel cells, solar cells and chocolate have in common ?Aging processes play a key role in the development of new functional materials. For example,when converting fuel, heat or sunlight into electrical energy, undesirable aging processes oftenresult in a large decrease in efficiency. Typically, these aging processes show up on very smallscales within the materials, i.e. in transformations of its microstructure. Both aging processes andperformance losses can be monitored experimentally. Using scanning electron and focused ionbeam microscopy, 2D or 3D microstructure images can be taken. In addition, the performanceof many materials can be determined using impedance spectroscopy. However, purely experi-mental approaches are insufficient to correlate in a quantitative manner the observed changes inmicrostructure to the resulting performance losses.This is where our computer models come into play. Using these models we simulate the underlyingaging processes based on physical laws to predict the resulting performance of the materialsstudied. Experimental microstructure data serve as input for the simulations. This way, modelingand simulation help us to better understand the aging of the materials – whether it be fuel cells,solar cells and chocolate. Anyway, as you will notice from the present Research Report 2012, ourresearch covers a broad range of exciting topics.At this point, I would like to take the opportunity to thank all the colleagues of our institute for theircommitment, their enthusiasm and the great mutual support. Thank you very much.

Thomas HockerHead of ICP

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1.1 Simulation von Personenströmen als Kontinuum bei Gross-anlässen und dichtem Personenverkehr

Contributors: R. AxthelmPartners: ASE GmbHFunding: KTIDuration: 2013–2014

Fig. 1: Street Parade in Zürich 2012(Quelle: http://www.streetparade.ch)

Die Simulation von Fussgängerströmen soll zu-künftig helfen, Grossveranstaltungen, wie z.B.die Zürcher Street Parade, so zu planen,dass auch in Paniksituationen keine Menschenzu Schaden kommen. Etablierte Multi-AgentMethoden sind nur auf kleine Menschenan-sammlungen anwendbar. Besser geeignet sindKontinuums-Methoden, für die aber bisher kei-ne kommerzielle Software erhältlich ist. Ziel desProjektes ist deshalb die Entwicklung einer Kon-tinuum basierten Software und deren Validie-rung durch Video-Analysemethoden.Der Anwendungsbereich solcher Simulations-rechnungen lässt sich nicht nur auf andereGrossveranstaltungen wie z.B. Fussballspieleerweitern, sondern auch auf Planungen undKonzeptionierungen von Gebäuden wie Bahn-steige, Bahnhofs- oder Flughafenhallen.Die Firma ASE ist spezialisiert auf videoba-sierte Erfassung von Personenströmen, agen-tenbasierte Simulation realistischer Szenarienund die ereignisorientierte Simulation der Aus-lastung von Serviceplätzen. Solche sogenanntemikroskopische Simulationen, die jeden Fuss-gänger einzeln darstellen, stossen bei hohenPersonendichten schnell an Grenzen, so dasskeine zuverlässige Analyse mehr möglich ist.Makroskopische Modellansätze versprechen insolchen Situationen bessere Rechenergebnis-se. Bis heute ist aber keine kommerzielle Lö-sung verfügbar.Der makroskopische Modellansatz von Perso-nendichten basiert zum einen darauf, die Men-schenmasse als Kontinuum anzusehen undzum anderen auf drei Hypothesen die für Per-

sonenbewegungen in grossen Dichten aufge-stellt werden: Erstens wird die Geschwindigkeiteines einzelnen Individuums durch die benach-barten Personen und das Verhalten der Mengebestimmt. Zweitens haben die Fussgänger eingemeinsames Ziel, das sie verfolgen. Und drit-tens nähern sich die Fussgänger auf dem direk-testen Weg ihrem Ziel, wobei sie grössere Per-sonendichten zu vermeiden versuchen. Anhanddieser drei Hypothesen lassen sich die Bewe-gung und die Dichteentwicklung der Menschen-masse als Kontinuum mit der folgenden Glei-chung beschreiben %t +∇·(% u) = 0, wobei % fürdie Dichte und u für die vektorielle Geschwin-digkeit der Personenmasse steht. Die betrags-mässigen Grössen der Geschwindigkeitsvekto-ren sind in Form von empirischen Daten (Fun-damentaldiagramme, s. Fig. 2) gegeben. DieRichtung wird dann durch Lage der Ziele unddie Dichteverteilung bestimmt. Zum Modellan-satz dazu gibt es Varianten in der Literatur.

Fig. 2: (Quelle: Seyfried: Steps toward the fundamental diagram -

empirical results and modelling, 2007)

Qualitativ machen die theoretischen Ergebnis-se der makroskopischen Modelle einen gutenEindruck. Allerdings wurden noch keine Metho-den entwickelt, diese Ansätze auch quantitativzu validieren. Für die praktische Anwendung derin der Forschung erarbeiteten Methoden ist einesoftwaretechnische Umsetzung notwendig. Dasim Projekt zu erarbeitende Software Tool solldies ermöglichen. Zusätzlich wird der Ansatz imEntwicklungsprozess an Hand von gemessenenPersonenströmen validiert werden.

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1.2 Materialcharakterisierung in der Lebensmitteltechnologiemittels Ultraschall-Verfahren

Contributors: T. HockerPartners: IDP-ZHAW, ZSN-ZHAW, ZPP-ZHAWFunding: SoE-ZHAWDuration: 2012

Ziel des Projekts ist die Entwicklung und Erpro-bung eines Ultraschall-Demonstrators, mit demim Labor in Realzeit die Veränderung von Ma-terialeigenschaften von Lebensmitteln detek-tiert werden kann – wie z.B. die Kristallisationvon Schokolade. Hierfür sollen Ultraschallsen-soren in verschiedene Konfigurationen und An-regungsmoden über die Auswertung von Schall-geschwindigkeiten und Schallabsorptionen inder Lebensmittelprobe auf ihr Potential hin un-tersucht werden.

Abschlussbericht,Sonderfinanzierung,der,SoE, , ,

,

1,

Titel:' Materialcharakterisierung'mittels'Ultraschall4Verfahren'für'die'Prozessoptimierung'in'der'Lebensmitteltechnologie'

Projektteam:' ' Thomas,Hocker,(ICP,,Projektleiter), , , ,

Olaf,Hoenecke,(IDP),

, , , Josquin,Rosset,(ZSN),

, , , Marcel,Rupf,(ZSN),

Adrian,Fassbind,(ZPP,,nachträglich,zum,Projekt,gestossen),

Regula,Kramer,(ZPP,,nachträglich,zum,Projekt,gestossen),

,

, , , , , , , , , ,

Gesteckten'Ziele'

Ziel,des,Projekts,ist,die,Entwicklung,und,Erprobung,eines,„UltraschallQDemonstrators“,,mit,dem,im,

Labor,in,Realzeit,die,Veränderung,von,Materialeigenschaften,von,Lebensmitteln,wie,z.B.,die,

Kristallisation,von,Schokolade,detektiert,werden,kann.,Hierfür,sollen,Ultraschallsensoren,in,

verschiedene,Konfigurationen,und,Anregungsmoden,über,die,Auswertung,von,SchallgeQ

schwindigkeiten,und,Schallabsorptionen,in,der,Lebensmittelprobe,auf,ihr,Potential,hin,untersucht,

werden.,

Erreichte'Ziele'

,

Der,UltraschallQDemonstrator,konnte,entsprechend,der,gemeinsam,erarbeiteten,Vorgaben,realisiert,

und,für,erste,Untersuchungen,genutzt,werden.,Die,Abbildung,zeigt,oben,links,das,am,ZPP,erstellte,

CADQModell,basierend,auf,der,thermischen,Auslegung,am,ICP,(exemplarisch,unten,links,dargestellt),

Fig. 1: Planung und thermische Auslegung desUltraschall-Demonstrators.

Der Ultraschall-Demonstrator konnte entspre-chend der gemeinsam erarbeiteten Vorgabenrealisiert und für erste Untersuchungen genutztwerden. Fig. 1 zeigt das am ZPP erstellte CAD-Modell basierend auf der thermischen Ausle-gung am ICP und den Vorgaben an die Ul-traschallsensorik von IDP und ZSN. Die Le-

bensmittelprobe kann über ein Peltierelementim Temperaturbereich 10 – 60 °C aufgeheiztund abgekühlt und so ähnlichen thermischenBedingungen wie in der Produktion ausgesetztwerden.In ersten Versuchen wurde gezeigt, dass mithochfrequentem Luftultraschall ein neues Ver-fahren für Top-Down Messungen über der Le-bensmittelprobe zur Verfügung steht (sieheFig. 2). Dieses neue Verfahren vermeidet dieSchwierigkeiten einer konventionellen, direktenSchallankopplung über flüssige oder feste Me-dien. Letztere dehnen sich in typischen Lebens-mittelherstellungsverfahren aufgrund von Tem-peraturänderungen aus oder ziehen sich zu-sammen und verfälschen so die Messungen.Der für Luftultraschall erforderliche Dynamikbe-reich von 120 dB konnte allerdings bisher nurmit Laborgeräten mit entsprechender Sende-leistung und hoher Verstärkung der Empfangs-elektronik erreicht werden. Mit zusätzlichen An-passungen der eingesetzten Wandler und derElektronik (kürzere Pulsdauer bzw. höhere Fre-quenz) wäre eine noch bessere Separation derempfangenen Echos zu erzielen.

Fig. 2: Aufgebauter Ultraschall-Demonstrator underste Messergebnisse. Das Ultraschallecho verän-dert sich wähnend der Erstarrung der Schokolade.

Der Ultraschall-Demonstrator soll längerfristigsowohl für den Einsatz in der studentischenAusbildung, als auch für Machbarkeitsanaly-sen als Basis für die Akquisition von zukünfti-gen Forschungsprojekten in der Lebensmittel-herstellung genutzt werden.

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1.3 Neuartig optimierte Kühlprozesse zur nachhaltigen Her-stellung von gefüllten Schokoladenprodukten mit verbes-serter Qualität

Contributors: L. Brenner, T. Hocker, T. Hunkeler, M. SuterPartners: IDP-ZHAW, ZSN-ZHAW, IFNH-ETHZ, Max Felchlin AGFunding: KTIDuration: 2012–2015

Das Projekt COOLCON hat zum Ziel, ei-ne neuartige in-line Messplattform (basierendauf Ultraschall-, Temperatur- und Wärmefluss-sensoren) in Kombination mit Multiphysik FE-Modellierung für die Analyse des transien-ten Erstarrungs- und Kontraktionszustandesvon Schokoladenprodukten zu entwickeln. DieMessplattform und die Modelle sollen für dieOptimierung der Kühlung der Schokoladenpro-dukte in industriellen Kühltunneln eingesetztwerden. Ziel ist die Verbesserung der Produkt-qualität unter gleichzeitiger Minimierung desKühlenergieverbrauchs.In der Schweiz wurden 2010 176’424 TonnenSchokoladenprodukte hergestellt. Um diese inFormen gegossenen Produkte in Kühlprozes-sen zur Erstarrung zu bringen, bedurfte es beieinem Fettgehalt von ca. 30 % einer Kühlener-gie von etwa 100 TJ (TeraJoule). Umfragenin der Schokoladenindustrie haben zudem ge-zeigt, dass zur Sicherstellung einer guten Aus-formbarkeit der Produkte als häufige Massnah-me eine Verlängerung der Produktverweilzeit imKühlkanal um 20–40 % realisiert wird.Jedoch kann bei Schwankungen in der Roh-stoffqualität von Kakaobutter und entsprechen-den Variationen in deren Kristallisationsneigungauch das Problem einer zu kurzen Verweil-zeit im Kühltunnel auftreten. Dies führt zu ei-ner Verschlechterung der Ausformbedingungenaufgrund einer unzureichenden Kontraktion desProduktes in der Giessform und damit zu Fehl-produktchargen.Deshalb soll durch eine Messdaten- und Modell-basierte Analyse der Kühlbedingungen und de-ren Auswirkung auf die Produktqualität der ne-gative Einfluss von Schwankungen in der Roh-stoffqualität minimiert und das grosse Energie-einsparungspotential besser genutzt werden.Erste Messungen wurden im Kühlkanal der MaxFelchlin AG, Schwyz, durchgeführt. Fig. 1 zeigtdie Anordnung der verwendeten Temperaturfüh-ler. Die Fühler wurden an verschiedenen Stel-len in der Schokolade, der Form und der Um-gebung platziert. Die resultierenden Tempera-turprofile sind in Fig. 2 dargestellt.

Fig. 1: Anordnung der T-Sensoren in Schokolade,Form und Umgebung.

Fig. 2: Abkühlkurven von Schokolade, Form und Um-gebung im Kühlkanal.

Parallel dazu wurde das Abkühlverhalten derSchokolade modelliert, siehe Fig. 3. Je nach-dem, ob die Änderung der inneren Energie uder Schokolade während der Erstarrung nurvon T , oder von T und der Kühlrate dT/dt ab-hängt, ergeben sich qualitativ unterschiedlicheT -Verläufe.

Fig. 3: Modellierter T-Verlauf der Schokolade im Kühl-kanal.

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1.4 Modeling the Cooling Curve of Soy Oil

Contributors: M. Suter, T. HockerPartners: Max Felchlin AGFunding: ICP-ZHAWDuration: 2012–2013

The crystallization properties of fats determinesthe melting behaviour, snap and gloss of choco-late and confectionery products. For a longtime, the ”Shukoff cooling curve method“ hasbeen applied in the food industry to analyze thecrystallization properties of fats. The Shukoffmethod is a standardized procedure which de-scribes the cooling of a properly melted fat in astandardized glass flask with a vacuum jacket.The glass flass is positioned in a water bath,while the temperature of the fat is recorded witha Pt100 temperature probe, see Fig. 1.

Fig. 1: Shukoff flask with melted fat sample and Pt100probe. (Note that the flask is actually positioned ver-tically in a water bath.)

Fig. 2: Comparison of measured and simulatedShukoff cooling curves of soy oil for water bath tem-peratures of 0 and 10 °C.

The objective of this work is to characterizethe Shukoff apparatus from a thermodynamicpoint of view. For this purpose, the cooling ofsoy oil has been modeled by global energy bal-ancing and by solving the local heat conduc-tion equation using our in-house multi-physicsFE-software SESES. Fig. 2 shows the goodagreement between the measured and simu-lated cooling curves for the considered soy oil

probe and for water bath temperatures of 0 and10 °C, respectively. Note that the simulatedcurve based on the global balance fits the databetter than the curve obtained from the FE-model. This is because the global model con-tains an adjustable fit parameter which the FE-model does not. Furthermore, the FE-model ismuch more sensitive with respect to parametervariations such as the thicknesses of the glasswalls of the used Shukoff flask, or the providedinitial conditions.After the successful validation of both modelsby experimental data, the main heat fluxes havebeen calculated. In Fig. 3, you can see fromJradiation,Wat that the thermal radiation betweenthe soy oil probe and the surrounding coolingwater is dominant – even at these rather lowtemperatures.

Fig. 3: Heat fluxes between the soy oil probe and itssurroundings as obtained from the developed SESESFE-model.

However, the non-negligible conductive heatflux Jcon,Wat through the vacuum gap at vacuumpressures around 1 Pa indicates the presence ofheat transfer by Knudsen flow. Finally, it is obvi-ous from the behavior of JAmbient that at coolingtimes above 40 minutes, heat flows from the am-bient air above the cooling water level into theprobe. This leads to a stationary probe temper-ature which is above the cooling bath tempera-ture, see Fig. 2.In future work, our modeling approach will beextended to phase change materials such ascocoa butter and to other cooling curve appara-tus such as tempermeters. This will help to bet-ter understand the complex crystallization be-havior of chocolate and confectionery products.

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1.5 Virtual Layout for Continuous Casting of Steel

Contributors: G. SartorisPartners: SMS Concast, Numerical Modelling GmbHFunding: CTIDuration: 2012–2013

SMS Concast is an engineering company sup-plying heavy machinery and related technologyfor the production of long steel products as bil-lets and blooms, which are subsequently trans-formed by rolling or forging into semi-final prod-ucts. SMS Concast is selling combi continuouscasters by exploiting its lead in casting processknow-how and innovative customer-specific de-sign solutions. The core components relevantfor the steel-making processes as melting, re-fining and casting are designed and developedin Zürich and Udine (Italy). The scope of sup-ply of SMS Concast comprises design, engi-neering and automation, supply of hardware,commissioning of single process elements up tocomplete melt-shops. Such melt-shops rangein their capacity from ca. 150.000 tons/yearup to 2.3 million tons/year for one process-line.The company is acting world-wide and oper-ates in the growth markets for steel with itsown 100% owned daughter companies in Brazil,North America, Italy, India, China, Thailand andat European locations in England and Spain.

Goal of this project is to provide the industrialpartner SMS Concast with up to date softwarefor modeling the continuous casting of steel.In particular, our aim is to improve and adaptthe NM-SESES multiphysics software to state-of-the art numerical algorithms as required forrunning optimized computations in the layout ofcontinuous casting machinery. The NM-SESESsoftware is already an advanced numerical toolfor multiphysics modeling. It can solve in a cou-pled way almost all conservation laws of clas-sical physics with generic coupling terms andmaterial laws defined by the user as part ofthe problem specification. However, due to thecomplexity of the problem at hand, the problemspecification for the continuous casting modelis becoming a rather involved task. With thisproject, SMS Concast plans to improve the nu-merical simulation know-how developed in col-laboration with NM Numerical Modelling GmbHduring the past years. Optimized models andsimulation concepts for the moving strand ap-proach will enable SMS Concast to simulatecasting processes closer to reality, with less ef-

fort and deploy it already in the offering phase.In addition, it will support R&D by identifica-tion of casting process limits and troubleshoot-ing during installation and the after sales phase.The continuous casting of steel includes a liq-uid phase inside the moving slab and a so-lidifying one at the exterior. The liquid phasecan display a turbulent character whereas thesolid one is subjected to elasto-plastic deforma-tions. The strand is moving in a stationary waythrough rollers and at the same time is cooledby sprayed water. Numerical methods have tocope with solid and fluid phases transport, en-ergy transport, mechanical contacts, radiationand cooling. Here a mixed Euler-Lagrange for-mulation should be used to model this multi-physics problem, the former one is the methodof choice for fluids and the latter one for solids.The challenging task is the capability to cor-rectly track the evolution of the surface showingthe phase transition, in short front tacking. Acoupled thermal-mechanical computation is re-quired here with an enthalpy function stronglynon-linear at the phase transition. The solid-ified portion of the slab undergoes large plas-tic deformations and grows inwards from a thinlayer to the full solid slab. For modeling the me-chanical behavior of thin structures, shell ele-ments are generally preferred. However, sincethe slab’s walls are standing growing in thick-ness, at some point one has to switch to genericsolid elements, because the shell hypothesis isnot valid anymore. To avoid this critical switch-ing, one can opt to use stabilized solid elementsof first order from the beginning.

Fig. 1 Steel blooms produced by SMS Concast con-tinuous casters.

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1.6 Pore Clogging During a Long-Term Experiment with Ben-tonite Buffer Material: Pore-Space Percolation and Predic-tion of Air Permeability

Contributors: L. Keller, L. HolzerPartners: EMEZ-ETHZ (P. Gasser), EMPA (M. Rossell, R. Erni)Funding: NAGRA, SHARCDuration: 2012

Low-permeability geomaterials such as clayrocks and betonites are potential seal materi-als that should guarantee the safety of radioac-tive waste depositories. In addition, such ge-omaterials are reservoirs of natural gas, whichwere increasingly exploited during recent years.Therefore, gas flow properties of such materialsare of prime importance because, for example,gas pressure form corroding steel in radioactivewaste depositories should be released via theintergranular pore space. Thereby, one of themost fundamental question is, at what proper-ties (e.g. porosity) gas can flow trough the porespace and arrive at the other side of the sys-tem. By using a combination of high-resolutiontomography, local porosity theory1 and classi-cal percolation theory we provided informationon fundamental transport properties such asthe percolation threshold2. In the following wepresent results related to one of the case stud-ies that where performed at the ICP. The ex-amined bentonite samples are from the long-term experiment, which simulates the behaviourof different seal materials under conditions of ahigh level radioactive waste depository.

The microstructure analyses document that ex-tensive precipitation of amorphous material ledto substantial changes of the pore structure. En-ergy dispersive X-ray spectroscopy performedin a transmission electron microscope showsthat the amorphous material is enriched in Fe,Ca and Si, which indicates that Fe released fromcorroding steel reacts with dissolved speciesfrom the buffer material. Initially the porosity inthe bentonite was in the range of 4.3–4.6 vol. %but due to precipitation and pore clogging theopen porosity was reduced to < 1 vol. %.

Focused ion beam tomography in combinationwith a finite scaling approach was applied to theresolved pore space, which yielded percolationthresholds with critical porosities φc (Fig. 1).After precipitation the residual open porosity isfar below the percolation threshold. The origi-nal porosity of one sample was above the per-colation threshold, but also in this material thepercolation is restricted to one spatial direction.

This indicates an anisotropy with respect to per-colation. Obviously, precipitation of new phasesleads to pore clogging, which in turn affects gaspermeability. Using results from pore-networkmodelling3 in combination with percolation the-ory illustrates that a minor reduction of porosityleads to a to substantial decrease in gas perme-ability. Depending on water saturation, air per-meability decreases exponentially over three tofour orders of magnitude within a narrow poros-ity range of about 1 vol. % (Fig. 2).

Fig. 1: Determination of percolation threshold φc Cal-culation of finite-size percolation probabilities λ(φ,L)are based on reconstructed pore spaces that wereobtained from of FIB tomographic data. (a) Mea-suring pore connectivity in cells of different sizes Lallows calculating finite-size percolation probabilities.(b) finite scaling of φmax (i.e. point inflection of λ(φ,L)with L−1/ν yielded percolation thresholds along dif-ferent directions.

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Fig. 1: Prediction of gas permeabilities related to apore space that is affected by changing porosities dueto segregation of new phases. (a) Gas permeabilitieska(φ) calculated for different values of water satura-

tion S. The absolute permeability k0 and the criticalvolume fraction εc for air percolation was calculatedon the base of two-phase flow network modelling. (b)and (c) are illustrations of two principle steps in thenetwork modelling workflow. (b) 3D reconstructionof the pore space after segmentation based on FIB-nt. (c) Representation of the extracted pore network(also called skeleton), which is topologically equiva-lent to the segmented pore space in (b). Red ballscorrespond to pore bodies whereas grey sticks corre-spond to the pore throats.

Based on observations and calculations, gastransport along the integranular pore space ofbentonites is not considered as a possible sce-nario and can reasonably be excluded for theresidual open porosity after segregation of newphases.

Literature:1Hilfer, R. 1991, Physical Review, 44, 60-75.2Keller et al. (subm.), J. Geophys. Res.3Valvatne, P. H., Blunt, M.J., 2004. Water Re-sources Research, 40, W07406.

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1.7 A New Developped Method for the Optimization of the Ad-hesion Strength of Ceramic and Metallic Coatings

Contributors: Y. Safa, G. Sartoris, T. HockerPartners: IMPE-ZHAW (M. Terner, D. Penner, Ch. Scherrer, A. Jung)Funding: SoE–ZHAWDuration: 2012–2013

Thermal barrier coatings (TBC) are an essen-tial technology in many industrial applications,from “macro applications” such as the ceramiccoating on the metallic blades in gas turbinesto MEMS (Micro-Electro-Mechanical-Systems)thin film deposition. Failure of such coatings oc-curs often at the coating-substrate interface.

Several experimental testing (shearing, tensile,or bending tests) have been suggested to eval-uate the adhesion strength of the coats. Suchmethodes, however, are not applicable in gen-eral, especially for the evaluation of the remain-ing interfacial strength of actual coated compo-nents in gas turbine, because of the requirementof relatively large specimen.

An alternative non-destructive test is based onindentation (by Vicker or Knoop) applied onthe interface of “small” coat-substrate sample.1

Moreover, the fracture toughness of the coatwhich is represented by the stress intensity fac-tor Kc is obtained using empirical formulationwith fitted parameters. An open question is stillthe applicability of such a semi-empirical ap-proach for different material and loading condi-tions.

The main objective of this project is to develop arelevant material model to assess the intarfacefracture toughness using physical parametersmeasured via X-ray diffraction (XRD), indenta-tion testing and sophisticated numerical tools forthe simulation of contact mechanics and crackpropagation in various coating-substrate sys-tems provided by current or past research part-ners. This is divided into three work packages:WP1- Indentation tests at the coating-substrateinterface to produce cracking and provide adepth-load dependency, followed by micro-scopic imaging of the indented samples.WP2- XRD measurement of residual stress inthese samples.WP3- Set up a numerical contact mechanicsmodel (FEM) and a numerical crack propaga-tion model by applying XFEM (eXtended FiniteElement Method) and using input material datafrom WP1 and WP2.

Fig. 1: A road map for search space

X-ray diffraction using a new 1/4 circle EulerianCradle was used for residual stress (RS) analy-sis of the samples. The measurement parame-ters were established and good residual stressvalues were obtained for PVD-ZrN, TBC bond-coat layer, and welded Stellite 712 on steel. Nosignificant residual stress was found in the topsurface of the TBC ceramic YSZ layer, howeverthe geometry did not allow accurate measure-ment at the interface. HOVF Cr2C3-NiCr hardcoatings were not suitable for this XRD analy-sis.

Fig. 2: XRD spectra for YSZ coating: except for the1 bondcoat peak indicated, all peaks are YSZ orsubstrate. Theoretical bondcoat peak positions areshown by green markers. (Performed at LKM by M.Terner)

A new indentation method is developed at thelaboratory of metallic material LMM to perform

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indentation tests along coating-substrate inter-faces from 5 to 500 N, with both Knoop andVickers indenters. The HOVF Cr2C3-NiCr hardcoating was the most successful system tested,whereas the TBC and Stellite system could notproduce reliable information.

Fig. 3: 3D confocal microscope image of indenta-tions taken with Leica DCM 3D. The indentation isapplied at the interface between YSZ coat and steelsubstrate using a Vickers indenter, for 14 micrometerdepth. (Performed at LMM by Ch. Scherrer)

A contact mechanics model based on the FEMsoftware SESES developed at ICP was ex-tended to indentations on a bimaterial interface.The numerical simulation was validated, sincethe obtained load-depth data are in good agree-ment with the values provided by indentation onsuperalloy sample.

Fig. 4: Simulation of superalloy sample under Vickerindentation using in-house developed SESES code.A plastic deformation is shown in unloading stage

The resulting contact stress fields were suc-cessfully used to predict the crack initiation andpropagation and to evaluate the fracture tough-ness in an advanced simulation based on XFEM(implemented in GetFEM package), see Fig. 6.

Fig. 5: The results obtained at ICP are in agreementwith experimental data at IMPE

Fig. 6: Interface indentation crack in slice view: Sim-ulation using XFEM and visualization using Paraview

Perspective:An implementation of advanced enrichmenttechniques in XFEM code representing the bi-material interface crack should allow more ac-curate representation of the stress field in de-lamination problem. An iterative coupling of thesolving step for crack growth and the contactsolution at given indentation depth step shouldbe a highly sophisticated approach of the crackgrowth under indentation. The fracture mechan-ics results obtained by solving a dynamic crackgrowth problem can be compared to the experi-mental data when acoustic emission techniquesare synchronized with operational time step ofthe indentation machine.

Literature:1 Yamazaki et al., Acta Metall. 24, No. 2, 109-117 (2011).

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1.8 Automatic Ice

Contributors: R. RitzmannPartners: ZPP-ZHAWFunding: Altira GmbHDuration: 2012–2013

In einer Vorarbeit wurde ein LED Bildschirmzum Einbau in Eisfelder von Eishockeyarenasentwickelt. Der Einbau und der damit ver-bundene schichtweise Eisaufbau, erwies sichaber als aufwändiger und lange andauernderProzess. Die damit betrauten Mitarbeiter habenlange in der Kälte auszuharren.Um den Vorgang zu automatisieren wurde inZusammenarbeit mit dem ZHAW internen Zen-trum für Produkt- und Prozessentwicklung einserienreifer Automat erstellt (siehe Fig. 1).

Fig. 1: 3D Kontruktion, kompaktes Eis System zumautomatischen Aufbau von klarem Eis

Automatic Ice enthält eingebaute Heiz- undKühleinheiten und kann Luft und Wasser invordefinierten Abläufen ins Eisloch spritzen.Zuerst wird das Eis auf eine definierbareTiefe abgeschmolzen und anschliessendschichtweise innerhalb von 4 mm/h wiederaufgebaut.Den hohen Ansprüchen an die Eisqualitätwird dabei Rechnung getragen. Es gibt also

keine Lufteinschlüsse und keine sichtbarenSchichtübergänge im fertigen Eis.Die Anlage wird zur Zeit im OLAB auf einerumgebauten Eiskühltruhe unter ähnlichen Be-dingungen wie in der Eishalle betrieben um dieSensorik und Parameter zu optimieren (sieheFig. 2).

Fig. 2: Labortests für optimierten Parametersatz

Mit Automatic Ice werden die LED-Bildschirm-Module oder auch Markierungen schnell ein-und ausgebaut. Zusätzlich bietet es auchdie Möglichkeit defekte Stellen, wie sie z.B.im Bereich der Eishockeytore häufig auftreten,über Nacht reparieren zu können.

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1.9 Diagnostic Device for the Early-Stage Detection of SkinCancer

Contributors: M. BonmarinPartners: Dermato Oncological Unit – HUGFunding: Swiss Cancer LeagueDuration: 2012–2014

Incidence of skin cancers is very high in Switzer-land and rising worldwide. Their prognosis de-pends on the precocity of diagnosis. Currently,the detection of skin cancer is essentially clini-cal and largely depends on the expertise of theclinician. Though, as early tumors often lack ofspecific signs, many benign lesions are excisedto be on the safe side. Moreover, some skin can-cers do not have visible limits, which can inducecomplex or multistep surgery. Therefore, detec-tion and treatment of these tumors generate bighealth costs.Compared to benign lesions, malignant tissuesare expected to demonstrate specific thermalproperties that can be exploited to refine their di-agnosis. For example, a higher metabolic activ-ity and a higher perfusion are anticipated at thelocation of the cancerous lesion. Such thermo-physical variations can be accurately detectedusing active thermography based setups.In close collaboration with the Geneva Univer-sity Hospital (HUG), we develop a new highlysensitive infrared imaging technique for the de-tection of skin cancers. We plan to test thistechnique in order to define its actual limitations.The device is based on the lock-in thermogra-phy method: skin surface temperature is period-ically modulated by forced convection, while ahighly sensitive infrared imaging device recordsits thermal emission (see Fig. 1 A)). Infrared im-ages are then processed to a computer accord-ing to the digital lock-in principle. We expect thatthe amplitude and phase images resulting fromthis demodulation can be correlated to the le-

sion malignancy.The first prototype developed in our laboratory(see Fig. 1 B)) shows promising results. An im-proved version will be tested in a clinical en-vironment in summer 2013 at the UniversityGeneva Hospital to evaluate the potential of themethod.

Fig. 1: A) Pictorial description of the lock-in thermog-raphy setup. B) First Dermolockin prototype devel-oped in our laboratory

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1.10 Produktionskontrolle von Pulverbeschichtungen mittelsthermischer Schichtprüfung

Contributors: N. ReinkePartners: IDP-ZHAW, IGP-ZHAW, Winterthur Instruments AG, J. Wagner AG, Ronal AG,

Ernst Schweizer AG, Ramseier Woodcoat AG (Ru)Funding: KTIDuration: 2012–2013

Pulverbeschichtungen zeichnen sich besondersdurch Korrosionsbeständigkeit und Kratzfestig-keit aus. Sie sind lösungsmittelfrei und werdenbesonders ressourcenschonend aufgebracht.Schwer kontrollierbare Prozessparameter wiedie elektrostatische Feldverteilung, Umgebung-stemperatur und die definierte Körnigkeit desPulvers wirken sich auf die Beschichtungsdickeaus, die bislang nur nach dem Einbrennvorgangzuverlässig geprüft werden kann. Verschwen-dung von Ressourcen und Beschichtungsfeh-ler sind die Folge einer fehlenden Prozessprü-fung bei der Beschichtung. Hohe Einbrenntem-peraturen und -zeiten verursachen zudem hoheEnergiekosten. Dadurch wird die Wirtschaftlich-keit von Pulverbeschichtungen im erheblichenMasse beeinträchtigt.

Fig. 1: CoatMaster Messsystem.

Im Rahmen dieses Projekts soll ein marktna-hes Messsytem entwickelt werden, welche ei-ne Kontrolle der Beschichtungsdicke vor demEinbrennen sowie des Gelier- und Aushärte-grads in der Produktion erlaubt. Dieses Mess-system erlaubt verkürzte Einfahrzeiten von Be-

schichtungsanlagen, eine bessere Auslastungdes Personals, eine Reduzierung der Beschich-tungsdicke auf das Optimum und eine 100%Qualitätskontrolle. Das Messystem hilft das Ver-ständnis des Einbrennvorgangs zu verbessernund ist damit ein Grundstein für ökonomischund ökologisch optimierte Pulver mit verrin-gerten Einbrenntemperaturen und effizienterenEinbrennprozessen. Als Grundlage für diesesMesssystem soll eine funktionstüchtige Pilotan-lage entwickelt und deren Praxistauglichkeit beiAnwendungspartnern getestet werden.

Fig. 2: CoatMaster bei der Inline-Schichtdicken-messung von Pulverbeschichtungen.

Das Projektkonsortium umfasst die gesamteWertschöpfungskette der Pulverbeschichtungs-industrie: Hersteller von Pulverlacken, Anlagen-bauer, Messgerätehersteller, sowie die Anwen-der. Im Anschluss an das Projekt sollen Feld-tests bei den Industriepartnern durchgeführtwerden. Die Erkenntnisse dieser Feldtests flies-sen in die Weiterentwicklung des Messsystemsein.

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2.1 Optimierung eines SOFC Brennstoffzellenmoduls

Contributors: T. Hocker, C. MeierPartners: IEFE-ZHAW (P. Diggelmann), Hexis AGFunding: Bundesamt für Energie, Swiss Electric ResearchDuration: 2012–2014

Zur Reduktion von Material- und Montagekos-ten entschied sich die Firma Hexis AG zurNeukonstruktion ihres Brennstoffzellenmoduls(BZM). Dabei stand nebst der Vereinfachungder Konstruktion auch die Verbesserung derTemperaturverteilung im Zentrum.In das Hexis-BZM sind nebst den elektrisch-chemischen Komponenten (Zellstack und Re-former) auch wärmetauschende Elemente in-tegriert, welche die Betriebstemperatur sowiedie Temperaturgradienten an der Zelle kontrol-lieren. Durch diese Bauweise kann das Hexis-System zwar kompakt gebaut werden, dafürsind die auftretenden Wärmeströme schwe-rer zu verstehen und zu kontrollieren. Diethermisch-fluidische Auslegung des neuen De-signs wird deshalb vom ICP, zusammen mitdem Institut für Energiesysteme und Fluid-Engineering (IEFE) der ZHAW, durch Modellbil-dung unterstützt.In der Konzeptphase konnten wir durch dieAnalyse der Massen- und Energieströme, dieCharakterisierung der wesentlichen System-komponenten sowie die Abbildung des BZM-internen Wärmetauschernetzwerkes einen op-timalen Betriebspunkt identifizieren. In einemnächsten Schritt erstellte das IEFE eine drei-dimensionale Strömungssimulation, welche die

Firma Hexis experimentell validieren konn-te. Dieses numerische Modell berechnet dasStrömungs- und das Temperaturfeld unter Be-rücksichtigung von Strahlungswärmetransport.

Der Brennstoffzellenstack wird optimal bei ei-ner Temperatur von 850 ◦C betrieben. Bei hö-heren Temperaturen führen Alterungsprozessezu einer erhöhten Degradation des elektrischenWirkungsgrades, während bei niedrigeren Tem-peraturen die inneren elektrischen Widerstän-de der Zellen sehr hoch sind. Deshalb sollteauch die axiale Temperatur-Ungleichverteilung("T-Bauch") vermindert werden (siehe Fig. 1),um den ganzen Stack im optimalen Tempera-turfenster betreiben zu können.

Anhand der Simulation des Ist-Zustandes konn-ten wir zeigen, dass der T-Bauch wesentlichdurch die Führung der Verbrennungsluft be-einflusst werden kann. Zusammen mit Hexishaben wir eine Vielzahl an Designs entwor-fen, simuliert und optimiert. Ende 2012 wur-de das vielversprechendste Konzept an einemVersuchsaufbau getestet. Trotz einer wesentlicheinfacheren Konstruktion resultierte eine Re-duktion des T-Bauches von rund 60 %. Gleich-zeitig verbesserte sich die Effizienz der thermi-schen Isolation markant.

Fig. 1: Temperatur-Plots der Referenz- und einer optimierten Variante. Der Zellstack der optimierte BZM-Variante weist einen geringeren Temperatur-Bauch auf.

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2.2 Leckagenanalyse im Hexis Brennstoffzellensystem

Contributors: L. KaufmannPartners: Hexis AGFunding: Swiss Electric Research, Bundesamt für EnergieDuration: 2012–2014

Die Hexis AG in Winterthur (ehemals Sul-zer Hexis) entwickelt ein mit Erdgas betrie-benes Hochtemperaturbrennstoffzellensystemvom Typ SOFC (Solid Oxide Fuel Cell) zur sta-tionären Strom- und Wärmeerzeugung in Ein-familienhäusern. Die Langlebigkeit und Zuver-lässigkeit dieses Systems hängt unter anderemmassgeblich von der Stabilität der zur elektri-schen und thermischen Energieerzeugung ver-wendeten Brennstoffzellen ab. Für stationärenBrennstoffzellensysteme ist ein entscheidenderErfolgsfaktor das Erreichen der geforderten Le-bensdauer von 40’000 Betriebsstunden. Im Be-trieb werden Brennstoffzellen durch thermische,chemische und auch mechanische Belastungbeansprucht. In Folge dessen nimmt der elek-trische Wirkungsgrad des Systems mit zuneh-mender Betriebsdauer ab. Diese Leistungsde-gradation wird beschleunigt, wenn eine Lecka-ge, z.B. durch eine defekte Dichtstelle odereinen Zellriss, auftritt. Dies kann auch kurzfristigeinen Einfluss auf die Leistung des Brennstoff-zellensystems haben.

Fig. 1: Brennstoffzelle mit Vorschädigung. Der Zel-le wurde ein radial verlaufender Schlitz hinzugefügt.Dies ist eine extreme Schädigung. Es ist unwahr-scheinlich, dass im Betrieb so starke mechanischeSchäden auftreten.

Um herauszufinden, wie sich mechanische Zell-schädigungen auf das Verhalten des Sys-tems auswirken, wurden in Kurzzeitversuchen

(<1000 h) Zellen mit einer definierten Vorschä-digung in Form von Schlitzen und Brüchenmit intakten Zellen verglichen. Zur Charak-terisierung des Zellverhaltens wurden Strom-Spannungskennlinien aufgenommen. Es zeigtsich, dass zur Detektion eines Zelldefekts ganzeStrom-Spannungskennlinien betrachtet werdenmüssen. Es reicht nicht aus, einzelne Merkma-le wie zum Beispiel die Ruhespannung (OCV)zu betrachten. Leichte Zelldefekte wie einfacheRisse lassen sich im Hexis-System in der Re-gel nicht über Strom-Spannungskennlinien de-tektieren. Bei schweren Schädigungen (0.8 mmbreite Schlitze) sind die Auswirkungen auf dieKennlinien deutlich erkennbar.

500

600

700

800

900

1000

1100

0 5 10 15 20 25

Spannu

ng/m

V

Strom / A

intakte ZelleZelle mit Schlitz

Ruhespannung

Fig. 2: Vergleich der Strom-Spannungskennlinien vonintakten und vorgeschädigten Zellen. Die intakte Zel-le weist eine deutlich höhere Ruhespannung auf alsdie Zelle mit Schlitz. Zudem fällt die Kennlinie dervorgeschädigten Zelle steiler ab, was sich negativauf den Innenwiderstand der Zelle auswirkt.

Im Betrieb kann davon ausgegangen werden,dass keine Schädigungen dieses Ausmasses(Schlitze von 0.8mm Breite) bei Zellen auftreten.Es bleibt festzuhalten, dass diese Aussagen nurfür Kurzzeitversuche zutreffen. In Langzeitver-suchen ist zu erwarten, dass durch die Defek-te verstärkte Zellschädigungen wie z.B. Delami-nation und/oder übermässige Degradation derElektroden auftreten und somit die Leistungsde-gradation merklich zunimmt.

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2.3 Topological Analysis and FE-Simulation for the Study ofMicrostructure Degradation in Solid Oxide Fuel Cells

Contributors: L. Holzer, L. Keller, O. Pecho, M. Neumann, T. HockerPartners: Hexis SA, EMPA, EMEZ-ETHZ, FZ-Jülich (De), Ulm University (De)Funding: EU-FP7 (Project: SOFC-life)Duration: 2012–2014

Solid Oxide Fuel Cell (SOFC) systems repre-sent an environmentally friendly energy tech-nology that efficiently converts chemical energyfrom natural gas into electricity and heat. In or-der to be economically profitable a service lifeof 40’000 hours must be reached. The complexphenomena of materials degradation are inves-tigated in the SOFC-life project by a Europeanconsortium, which consists of 20 academic andindustrial partners. The aim of the project is togain an improved understanding of the degra-dation mechanisms on a microscopic scale andof their impact on cell and stack performanceson a macroscopic scale. This will enable to im-prove durability, which also leads to a higherprofitability. In this project, the ICP is workingon the quantitative 3D characterization of theelectrode microstructure. The ICP also dealswith the challenging task, how this microstruc-ture information can be incorporated into a sim-ulation framework that allows prediction of thelong-term degradation behavior.

Fig. 1: Illustration of microstructure degradation ina fine-grained Ni-YSZ anode upon redox cycling at900 ◦C. The effective ionic conductivity is the prod-uct of the intrinsic conductivity multiplied by the mi-crostructure factor (σeff = σ0M ). The M-factor itselfis the product of four distinct topological parameters(M = φPβτ−1). The most significant microstructureeffect in this case is a significant drop of the constric-tion factor (β), which strongly affects M and σeff .

In order to understand microstructure effectsrelated to electrode degradation it is neces-sary to identify all topological features, which

have a significant influence on the cell perfor-mance. For this purpose dedicated techniquesfor 3D analysis including image modeling andnanotomography were developed over the lastyears. Fig. 1 illustrates the topological changesin YSZ of a Ni-YSZ anode before and after re-dox degradation. In each phase the effectivetransport properties (i.e. electronic conductiv-ity in Nickel, ionic conductivity in YSZ, gas dif-fusion in the pores) depends on four distinctparameters: phase volume fraction, percola-tion factor, tortuosity and constrictivity. Surpris-ingly, the ionic conductivity drops significantlyupon redox cycling due to a decrease of theconstrictivity in the YSZ phase. This new phe-nomenon has not been documented in literatureand the perception of it was only possible withnew 3D-techniques.In a second step the topological information isincorporated into a finite element model (FEM).The detailed 3D analysis tools provide a quan-titative description not only of time dependentdegradation of the bulk electrode, but also ofthe local microstructure variations within dif-ferent domains of the electrodes. For exam-ple the above-described constrictivity parameteronly becomes important for transport distanceslarger than a few microns, but it has no effectat short distances. In the FE-simulation the dis-tinction of such short and long rang effects hasa significant influence on the current distributionclose to the electrode-electrolyte interface andon the corresponding cell performance (ASR).In summary, the combination of 3D-topologicalanalysis with FE-modeling provides a uniqueframework for the realistic simulation of SOFCdegradation. These methodologies providenovel insight on fundamental degradation mech-anisms, which is necessary for further improve-ments of the long-term service life of the solidoxide fuel cell system.

Literature:L. Holzer et al., J. Mat. Sci. 48, 2934-2952,2013.L. Holzer et al., J. Power Sources (in press),2013.G. Gaiselmann et al., Comp. Mat. Sci. 67, 48-62, 2013.

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2.4 Oxide Scale on Interconnectors after 40’000 Hours FuelCell Operation

Contributors: M. Linder, L. Holzer, T. HockerPartners: Hexis SAFunding: Swiss Electric Research, Swiss Federal Office of EnergyDuration: 2012–2014

To provide a technical relevant amount of electri-cal energy several fuel cells have to be stacked.These cells are connected in series with metal-lic interconnects (MICs) which act as gas sep-arators and distributors for cathode air and an-ode fuel as well as current collectors from theseelectrodes (cf. Fig. 1). Interconnects have tofulfill different material requirements such as ex-cellent oxidation and corrosion resistance andhigh electric conductivity. Under solid oxide fuelcell (SOFC) operating condition with high tem-perature (> 600 ◦C), wet and carbon containingatmospheres the oxide scale formation is con-tinually promoted.

cathode side air channels (O2, N2)

anode side fuel channels (H2, CO, H2O, CO2, N2, CH4)

LSM coating

Cr2O3 scale

Cr2O3 scale

Ni mesh

cathode

anode

Cr5FeY2O3 (CFY)

Fig. 1: MIC configuration within a SOFC-stack. Onthe anode side the Cr2O3 formation takes place atthe bare surface and on the cathode side betweenthe alloy and LSM-coating.

The ohmic resistance caused by Cr2O3 scaleformation on metallic interconnects can signif-icantly contribute to the overall degradation ofSOFC stacks. For this reason oxide scalegrowth on Cr5Fe1Y2O3 (CFY) was investigatedby scanning electron microscopy (SEM) frompost-test samples that were operated in Hexisplanar SOFC-stacks under dual atmospheres(i.e. anode and cathode conditions) at tempera-tures around 900 ◦C. The study includes uniquetest results from a stack operated for 40’000hours. To analyze the inhomogeneity in scalethicknesses a dedicated statistical image analy-sis method has been applied (cf. Fig. 2).

Fig. 2: (Top) SEM image of a cross section of ametallic interconnect after 2’000 h exposure (850 ◦Cin air). The perimeter of the Cr2O3 scale is markedby a red contour line. (Bottom) From the segmentedand binarized SEM image a mean scale thickness iscalculated.

SEM images were as well used to comparethe qualitative micro-structural phenomena re-lated to MIC oxidation at different sample loca-tions. The observed differences between differ-ent sample locations may relate to locally differ-ent conditions such as temperature and watercontent. The Cr2O3 scale growth on the anodeside is found to be approximately twice as fastin comparison to the scale growth on the cath-ode side. Finally, based on our time lapse analy-ses with extensive sampling it can be concludedthat reliable predictions of scale growth requiresstatistical analyses over a period that covers atleast a quarter (i.e. 10’000 hours) of the requiredSOFC stack life time (40’000 hours).

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2.5 Relationships between 3D Topology and Reaction Kineticsin SOFC Electrodes

Contributors: O. Pecho, L. Holzer, T. HockerPartners: IfB-ETHZ, NonMet-ETHZ, EMEZ-ETHZ, Hexis AG, EMPA, Ulm University (De)Funding: Swiss National Science FoundationDuration: 2012–2014

Solid oxide fuel cells (SOFC) represent anattractive, alternative energy technology dueto the combination of its high efficiency andfuel flexibility. This project investigates themicrostructure-performance relationships, in or-der to establish criteria for new microstructureconcepts of improved SOFC electrodes. Thisgoal requires an interdisciplinary approach in-volving: (a) electrode fabrication with controlledvariation of the microstructure; (b) quantitativeanalysis of microstructure involving first andhigher order topological parameters; (c) exper-imental characterization of macroscopic prop-erties focused on the electrochemical perfor-mance; and (d) FE modeling of the electrodereaction mechanism including the simulation ofcombined effects from local morphology (mi-crostructure) and from intrinsic material proper-ties (e.g. surface exchange kinetics).

Fig. 1: Microstructures obtained at different sinteringtemperatures, which lead to variations in grain andpore size, surface area and associated electrochemi-cal performance.

In the first period of the project, thin nanoporouscathodes consisting of (La,Sr)CoO3 (LSC) weresuccessfully produced with the cost-effectivespray pyrolysis. LSC is a mixed ionic andelectronic conducting material (MIEC) that isparticularly suitable for intermediate- and low-temperature SOFCs. Overall, the LSC cathodesexhibit a very good performance, which is at-tributed to the nanostructure with small particlesize and well-distributed porosity. This is favor-able for oxygen exchange at the LSC/air inter-

face, which is believed to be the rate determin-ing process. Figure 1 illustrates LSC cathodeswith different microstructures. In order to betterunderstand the complex relationship betweenmicrostructure and electrode performance, theexperimental investigations are combined with3D analysis and with numerical simulations.

First order topological parameters (e.g. parti-cle size distributions (c-PSD), volume fractions,and surface areas) are determined based on2D SEM imaging. For higher order topologi-cal parameters, (e.g. percolation factor, con-strictivity, tortuosity) 3D information is needed.FIB-tomography, which is the most suitable 3D-technique for this purpose, is time consumingand the number of 3D analyses is limited. In or-der to acquire 3D topological information for alarge number of different microstructures, newapproaches based on the combination of 2Dimaging and stochastic 3D simulation are cur-rently developed for this study in collaborationwith Empa and Ulm University.

In the present project the reaction mechanism ofan existing FE-model at ICP is adapted for MIECmaterials. For the simulation of microstructureeffects, input is used from microstructure anal-ysis (i.e. surface area, TPB, tortuosity, con-strictivity) and the effective transport properties.Special techniques were developed, which allowthe determination of effective transport proper-ties from topological analysis because the ex-perimental measurement is often very difficult(e.g. ionic conductivity of MIEC materials or gasdiffusivity in nanoporous thin films). In this waydifferent scenarios for microstructure effects canbe simulated in a realistic way, which helps tounderstand the complex pattern revealed by theexperimental investigations.

In summary, the combination of experimental in-vestigations together with 3D-imaging, stochas-tic simulations and numerical modeling opensnew possibilities to make links between topol-ogy, fabrication parameters and electrode per-formance. These methods shall thus be appliedin the next phase of the project for the improve-ment of LSC cathodes as well as for other com-posite electrodes.

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2.6 Thin-Membranes Design in Micro-Solid Oxide Fuel Cell

Contributors: Y. Safa, T. HockerPartners: NIM-ETHZ, LTNT-ETHZ, CSEM, SAMLAB-EPFL, MNT-NTBFunding: Swiss National Science FoundationDuration: 2010–2012

Since more than 10 years, a consortium of re-search groups from five Swiss centers havebeen involved in the development of µSOFC as“small" energy converter device. In November2012 a successful operation of the completesystem was demonstrated at ETH Zurich, seeFig. 1.The principal part of µSOFC, (as depicted inFig. 1 part (5) and in Fig. 2), includes electrodesand electrolyte membranes. The challengingcontribution of our institute during 2012 wasto provide a validated guideline design for thelayered membranes system under both man-ufacturing and operational conditions. In ourplanar design, thin film YSZ (yttria-stabilised-zirconia) electrolyte layers were fabricated usingpulsed laser deposition (PLD). The fabricationis accompanied by large residual compressivestresses that cause the electrolyte to buckle.This buckling behaviour was investigated basedon various experimental methods, analytical es-timations, and numerical simulations.

Fig. 1: Demonstration of µSOFC system. Lab onchip: Bieberle-Hutter A. et al. (2012), 4894-4902

Fig. 2: µSOFC: membranes (left), carrier and electri-cal board (right) in the scale of portable device.

Experimentally, the films have been investigatedby wafer curvature, light microscopy, white lightinterferometry and nano-indentation. The par-tial release of residual stresses in the film dur-ing free etching of the substrate was estimatedby a new method combining pre-etching opti-cal measurements with posteriori stress anal-ysis. An energy minimization procedure wassubsequently applied in combination with theRayleigh-Ritz method to determine the variousbuckling modes, evaluate the buckling ampli-tudes and determine the threshold values for in-stability transitions. Comparisons between sim-ulation results and experimental data show ex-cellent agreement and demonstrate the capabil-ities of this method to predict various bucklingstages of free-standing thin films.Finally, a new post-buckling design space forthin-film electrolyte fabrication has been ob-tained by applying a stress-based failure crite-rion, see the following figure.

Fig. 3: The design space for the fabrication of thinYSZ films is shown. The x-axis represents the sidelength-to-thickness ratios whereas the y-axis repre-sents the residual strain of the film. Under com-pression, i.e. for negative strains, pre-buckling onlyexists in a narrow region above the curve of the firstbuckling. The first and the second post-buckling re-gions located below the dashed curves c1 and c2represent zones of high tensile stresses that have tobe avoided. However, the post-buckling region alsoincludes large safe zone located above c1 and c2.Therefore, post-buckling design provides various op-tions for a safe selection of deposition conditions andmembrane dimensions.

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2.7 Belenos Fuel Cell Stack: Simulation and Freezing

Contributors: J. Schumacher, B. Perucco, G. SartorisPartners: PSI, Belenos Clean PowerFunding: Swiss Federal Office of Energy, Belenos Clean PowerDuration: 2010–2014

IntroductionProton exchange membrane (PEM) fuel cellsgenerate electrical power from hydrogen gasand currently undergo intensive research anddevelopment. PEM fuel cells are applied fortransportation, back-up power, portable powerand small distributed generation.Belenos Clean Power, in cooperation with thePaul Scherrer Institute develops PEM fuel cellsystems for passenger vehicles. Certain re-search aspects become relevant for further de-velopment of these fuel cells. In this projectwe develop coupled (or multiphysics) models torepresent the interaction between the transportand reaction processes that are present in anoperating PEM fuel cell. Analyzing these inter-actions by combination of simulation and mea-surement is essential to identify the energy con-version losses and to improve the fuel cell per-formance. The Paul Scherrer Institute providesthe experimental background for model valida-tion and calibration.

Modeling approachesTransport processes of mass, charge and heaton different length scales of the fuel cell com-ponents have to be analyzed to understand andimprove the performance of the fuel cell. In theproject we focus on two different approaches:1. We develop a membrane electrode assem-bly (MEA) model that represents the electro-chemical reactions and the transport processesin the through-plane direction of a proton ex-change membrane fuel cell. 2. We developa 2+1D model of a large-area PEM fuel cell.The 2+1D approach captures the essential fea-tures of the coupled transport and reaction pro-cesses, and it is suitable to take the high as-pect ratio between the in-plane and the through-plane dimensions of fuel cells into account. Inthe 2+1D model the gas flow-fields of the PEMfuel cell on the anode side and the cathode sideare numerically discretized in two dimensionsby using a finite element method. This allowsto calculate the pressure and velocity distribu-tions in the gas flow-fields. The coupling be-tween two opposing elements of the anode andcathode side is established by the 1D model(see above) representing the MEA. The trans-port processes for mass and charge and the

electrochemical reactions are accounted for inthe model by a nonlinear coupled system of par-tial differential equations.With the computation-ally efficient 2+1D model we intend to investi-gate different large-area fuel cell designs.

Sensitivity analysisIn 2012 we performed a sensitivity study of theone-dimensional MEA model. Thereby, we iden-tified the most important model parameters. Theinvestigated model parameters have different in-fluence on the simulation results, i.e. the currentdrawn from the cell, the average water contentor the maximum temperature to be reached inthe MEA. The influence of the parameters onthe simulation results depend on the operatingpoints on the current voltage curve of the cell.To determine the sensitivity of a parameter on aspecific simulation result, a base case value forall the parameters is defined resulting in a basecase simulation for the simulation like the cur-rent, for example. The investigated model pa-rameters were varied within a certain range ofvalues. The simulation results with variable pa-rameters were compared to the simulation re-sults obtained for the base case to evaluate thesensitivity.

Validation of the MEA modelQuantitative predictions with a fuel cell modelcan only be achieved if the model is carefullyvalidated. In 2012 we focused on the valida-tion of the electrochemical model description. Asmall area test fuel cell was used to validatedthe electrochemical part of the MEA model. Thecell voltage was measured as a function of themolar fractions of oxygen and hydrogen, thetemperature and the current density.

Flow-field simulations in three dimensionsWe performed an evaluation study to design dif-ferent gas distribution flow-fields. A gas flow-field design with parallel channels was inves-tigated and three-dimensional flow-field calcu-lations were performed by solving the incom-pressible Navier-Stokes equations with a finiteelement code. In this way we calculated thepressure distribution and the velocity field in thechannels. The aim of the study was to achieve a

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homogeneous pressure drop over the gas distri-bution channels. Different gas inlets and outletdesigns were investigated and different gas mix-ture volume flows were used as boundary con-ditions at the inlet and outlet. Furthermore, con-sumption of the reactant gases in the gas dis-tribution channels was modeled. Depending ongas consumption, this requires the gas distribu-tion channels to narrow towards the outlet of theflow-field to achieve a minimum pressure drop.This is essential to force the water out of the

channels. Some simulation results can be seenin the figure, where the pressure distribution andvelocity field of an actual flow-field are plotted.In the presented case, for example, it can beseen from the pressure distribution plot that thepressure distribution is not homogeneous overa defined cross-section of the gas distributionchannels. These 3D gas flow simulations areimportant to establish reference cases that canbe compared to the simplified 2+1D simulationapproach.

Simulated three dimensional pressure distribution (left) and velocity field (right) of a straight-channel gas flow-field of a PEM fuel cell. The incompressible Navier-Stokes equations were solved. Boundary conditions forthe flow-field at the inlet and the outlet were defined by known volume flow of the gas mixture. We assumeddepletion of the gas in the gas distribution channels.

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3.1 Exploring and Improving Durability of Thin Film Solar Cells

Contributors: T. Lanz, M. Schmid, C. Kirsch, B. RuhstallerPartners: FP-EMPA, TF-EMPA, LPI-EPFL, PV-Lab-EPFL, CSEM, SUPSI, BASF, AM-

COR, Solaronix, Oerlikon Solar, Pramac, Flisom, FluximFunding: Competence Center Energy and MobilityDuration: 2011–2013

The efficiency of thin film solar cells deteriorateswith time due to degradation phenomena. TheCCEM-CH project DURSOL aims at improvingthe understanding of the fundamental mecha-nisms underlying the degradation. ICP’s taskwithin the project is to advance and extend thenumerical models of the various solar cell typesbeing investigated.

Fig. 1: Calculated steady-state heating distributionin an amorphous silicon thin-film solar module in thedark for Vapp = −4 V. An artificial shunt was added inthe module creating a short circuit between two backcontacts.

The performance of thin film solar modulesmay deteriorate due to the degradation of theelectrical conductivity of transparent electrodescaused by water ingress. As the water diffusesinto the module from the edges, a spatial rep-resentation of the module is required to assessthe influence on the module performance. To in-vestigate the kinetics of water ingress and otherlocalized defects, we have developed a finiteelement method (FEM) model of the electro-thermal transport in thin film solar modules. Themodel uses a computationally efficient 2+1Dmodeling approach. Using amorphous siliconmini solar modules we have experimentally vali-dated the model using current-voltage measure-

ments under partial shading and lock-in ther-mography measurements. In Fig. 1 we showthe computed local heating rate in the mini mod-ule with artificially added shunts. The modelthus allows for a quantitative interpretation ofthe temperature measurements obtained withlock-in thermography. We will use the model tostudy the performance degradation due to wateringress based on measured diffusion patterns.In close collaboration with the industrial partnerFluxim AG transient electrical characterizationtechniques for solar cells have been developed.The measurement setup is capable of carryingout dark-CELIV, photo-CELIV as well as light-pulse photocurrent responses. The measure-ments allow for extracting material parameterssuch as the electron and hole charge mobili-ties. In Fig. 2 we show dark-CELIV measure-ments of CIGS solar cells from EMPA. From theobserved peak time we can estimate an effec-tive mobility of 0.35 cm2/Vs, which is in agree-ment with the expectations for this type of so-lar cell. We note that the experimental setupis able to resolve the dynamic transport withsub-microsecond resolution, as demonstratedby this high-charge-mobility solar cell.

Fig. 2: Measurements of the transient current re-sponse to linearly increasing voltage (CELIV) rampsfor various offset voltages for CIGS solar cells.

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3.2 Simulation of Hydrogen Production with a Photoelectro-chemical Solar Cell

Contributors: P. Cendula, J. Schumacher, M. SchmidPartners: LPI-EPFLFunding: Swiss Federal Office of EnergyDuration: 2012–2014

IntroductionElectrical energy consumption peaks at day andlowers at night. Solar energy production variesbetween summer and winter and it depends onclouds as well. Therefore, large effort on energystorage solutions is undertaken to balance ourenergy usage with renewable energy produc-tion. Hydrogen is one of the main candidates forsuch energy storage solutions, because it is anexcellent and clean fuel. One obvious solutionto renewable hydrogen production is the elec-trolysis of water with input of renewable electricenergy. Another promising alternative to the lat-ter is a photoelectrochemical (PEC) water split-ting solar cell, which could be a cheaper singledevice. A PEC cell absorbs light like a conven-tional solar cell, but the generated charges areused to drive a water reduction and oxidation re-action in the aqueous electrolyte to produce hy-drogen and oxygen, see Fig. 1.

Fig. 1: Photograph of a simple PEC cell for watersplitting. Courtesy of the Laboratory of Photonicsand Interfaces, EPFL Lausanne.

Motivation The current challenge is to findcheap materials with excellent suitability forPEC cells. Metal oxides such as hematite (ironoxide) and copper oxide have shown certainpromise with respect to hydrogen production,but they need to be understood and optimizedin order to become economically viable. Nu-merical simulation is crucial for improved un-derstanding and predicting the behavior of PECcells and for the characterization of appropriatematerials for PEC cells.

Model In collaboration with LPI EPFL, ICP is de-veloping a physical model of the light absorp-tion, energy-band alignment and charge trans-port in the PEC cell. The optical model is basedon forward ray-tracing to simulate the fraction oflight that is absorbed, reflected or transmittedthrough the PEC cell. The electrical model con-sists of electron and hole continuity equationscoupled with Poisson’s equation for the electricpotential. The electrical model is numericallysolved to calculate the current vs. voltage char-acteristics or impedance spectra of PEC cells.Results In 2012, we implemented a software tocalculate an energy-band diagram of a PEC cell,see Fig. 2. At this stage, the software plots theenergy-bands adopting the analytical solution ofthe Poisson equation for electric potential. How-ever, we also developed a numerical solution ofthe Poisson equation, which will be used later inthe project. For example, one can deduce theability of hematite to oxidize water because itsquasi-Fermi energy of holes E∗

F p is below thewater oxidation potential Eox. By varying thematerial parameters like bandgap energy, diffu-sion length of holes etc., their effect on the abilityto oxidize water can be understood. Since thePEC cell community often refers to the energy-band diagram only with qualitative argumenta-tion, our energy-band diagram improves the un-derstanding of PEC cells for various materialsand resolves some inconsistencies found in thePEC literature.For the optical model, optical reflections weremeasured at EPFL for standalone Quartz andGlass-FTO and also for a complete PEC cellwith hematite. Currently, we are collecting ma-terial data for the spectral refractive index andthe extinction coefficient of the individual layers,which will enable analysis of optical losses in theindividual layers.Outlook Currently, we are working on an exten-sion of the electrical model to account for thesurface states in the semiconductor and a tran-sient numerical model to simulate ac impedancespectra. Furthermore, we are developing an op-tical model to simulate the reflection and the ab-sorption of light. The simulation results are com-pared with measurements of PEC cells that areperformed at EPFL.

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Fig. 2: Snapshot of the energy-band diagram of a PEC cell with n-type hematite (implemented in Mathe-matica). Material parameters can be interactively changed to see their effect on the energy-band positions.The common scale of electrochemical energy is used : the left axis shows an energy with respect to thenormal hydrogen electrode (NHE) and the right axis with respect to the reference hydrogen electrode (RHE).Conduction and valence band edges of the semiconductor separated from electrolyte, ECB and EV B , areshown as dashed lines. Upon contacting the semiconductor with electrolyte, a space charge region is formedin the semiconductor which causes the bending of band edges (shown as solid lines). An applied bias po-tential Va further increases the band bending in the semiconductor and shifts the semiconductor Fermi levelEFn = EFp down. Upon illumination, the concentration of photogenerated holes dramatically increases asreflected in their quasi-Fermi level E∗

Fp. Electrochemical potentials for oxidation and reduction of water aredenoted Eox and Ered, respectively. The Fermi level in the metal EF,metal is automatically adjusted by poten-tiostat to enable hydrogen evolution at the metal (with certain overpotential above Ered).

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3.3 Integration of High Temperature Electric Converter for Elec-tricity Generation in a Solide Oxide Fuel System

Contributors: M. SchmidPartners: SSC-EMPA, LPCM-EPFL, ITP-ETHZ, CRISMAT-CNRS (Fr), Hexis AGFunding: Competence Center Energy and Mobility, Swiss Federal Office of EnergyDuration: 2012–2016

Solide oxide fuel cells (SOFCs) convert chemi-cal energy stored in a fuel (hydrogen or naturalgas) to electricity. The combustion of the fuelin the SOFC leads to waste heat of tempera-tures up to 900 ◦C. When the SOFC system isintegrated in buildings, the waste heat is usuallyused for hot water production. However, usingthermoelectric converters (TECs) a part of thewaste heat may be converted to additional elec-tricity, which is the most valuable form of energy.The goal of this project is to develop a thermo-electric converter for the implementation into theSOFC system of Hexis AG.Thermoelectric converters consist of thermo-electric legs made of two different semiconduc-tor materials (see Figure 2). The legs are con-nected electrically in series and thermally in par-allel. If a temperature gradient is applied alongthe legs an electrical potential difference be-tween the hot and the cold side is formed. Thepotential difference is due to the so called See-beck effect. The potential difference leads toan electrical current flowing through the thermo-electric legs. The working principle of a TECcontaining a single thermoelectric couple is il-lustrated in Figure 1.

Fig. 1: Working principle of a TEC built with two ther-moelectric legs.

Low temperature TECs are already available onthe market. These TECs are attached to hotparts of motors or stoves. However, for highertemperatures above about 300 ◦C the appropri-ate materials still have to be developed.

Fig. 2: Thermoelectric Converter. Image Courtesy:EMPA

These materials not only have to resist thehigher temperatures, they also have to combinesome competing physical properties: high elec-trical conductivity and thermolectric effect, but atthe same time high thermal resistivity. Ideal can-didate materials include perowskite-like metaloxides. These candidate materials are devel-oped and investigated at SSC-EMPA in orderto construct high temperature TECs to tempera-tures up to 900 ◦C.The work task of the ICP in this project is to de-velop a physical model for these high tempera-ture TECs. The model is used to simulate tem-perature, electric potential, current and heat flowdensity distribution inside the TECs. In Figure 3,we show the electric potential distribution insidethe two TEC legs along the central line.

Fig. 3: Electric potential inside the TEC legs alongthe central line (black and blue lines are for the n-type and p-type leg respectively). The temperaturedependence of the material properties is taken intoaccount.

The simulations allow to derive guidelines forthe optimal design of the TEC modules and toquantify the different energy conversion losses.

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3.4 Thermofluiddynamische Modellierung von Biomasseverga-sung

Contributors: G. Boiger, T. Hocker, C. MeierPartners: KeineFunding: Gebert Rüf StiftungDuration: 2009–2013

Die Vergasung von Biomasse wie zum BeispielHolz bietet die Möglichkeit, einen stückförmi-gen, festen Energieträger in eine Gasphase mithoher Energiedichte und Homogenität umzu-wandeln. Dieses Konzept hat bedeutende tech-nische Relevanz und gilt als Verfahren mit Po-tential.Mit heutigem Stand der Technik fällt es nachwie vor schwer grosse Biomassevergasungsan-lagen mit ausreichender Rentabilität zu betrei-ben. Einer der Hauptgründe dafür ist die hoheWartungsintensität derartiger Aggregate. Diesist unter anderem darauf zurückzuführen, dasskaum flexible und konsistente Konzepte zur dy-namischen Anpassung der wichtigsten Anla-geparameter an variierende Brennstoffqualitä-ten existieren. Zur effizienten Anlagenbetreu-ung benötigt der Betreiber eine Steuerung, oderzumindest einen Leitfaden, welcher die wich-tigsten Regelgrössen des Vergasungsprozes-ses (wie z.B.: Prozessluftzufuhr, Produktgas-rückführung, Prozessluftvorwärmung) an die Ei-genheiten des momentan zugeführten Rohstof-fes (wie Porosität der Schüttung, Permeabilität,Heizwert, Feuchtegehalt) anpasst. Thermofluid-dynamische Modellierung des Vergasungspro-zesses kann einen derartigen Zusammenhangherstellen und somit dazu dienen Regeln für dieSteuerung von Anlagen beliebiger Größe abzu-leiten.Am ICP wird zunächst an einem möglichst kom-pakten, ein-dimensionalen, thermofluiddynami-schen Modell des Vergasungsprozesses gear-beitet. Dieser Ansatz soll sich auf eine verein-fachende, aber grundlegende, analytische Auf-arbeitung des gekoppelten Multiphysikproblemsdes Vergasungsprozesses stützen. Dabei sollenbereits viele, physikalisch relevante Teilbereicheder Vergasung eines vereinfachten Biomasse-partikels miteinbezogen werden. Es sind dies:Die Zufuhr der Prozessluft in die Biomasse-schüttung; Der Stofftransport des Sauerstoffes

an die Reaktionszone des einzelnen Biomas-separtikels; Die Umwandlung der Prozessluft inein Gemisch aus Luft und Produktgas; Der kon-vektiv – diffusive Entropieaustausch zwischenPartikel und Produktgas – Luft Gemisch; Diethermisch getriebene Pyrolyse der Biomasse;Die thermodynamisch und stöchiometrisch be-stimmte, als Vergasung bezeichnete, Reakti-on der Edukte zu Kohlenmonoxid, Wasserstoff,Kohlendioxid, Methan, Wasserdampf und Sau-erstoff, aber auch Kohle und teerigen Rückstän-den; Die Einstellung eines thermodynamischenGleichgewichtes des Produktgases in Abhän-gigkeit der vorherrschenden Temperatur; DieErmittlung der Energiebilanz sowie der Reakti-onsenthalpie der Partikelmaterie, sowie die Wei-tergabe abströmender Materie und Entropie andarauffolgende Partikelberechnungszellen.

Dieses ein-dimensionale Vergasungsmodell sollmöglichst modular aufgebaut sein, um durchdiverse Untermodelle (z.B. zur detailliertenBeschreibung der Partikeltemperaturverteilungbzw. dem Abdampfverhalten der Partikel-feuchtigkeit) ausgebaut werden zu können.Das ein-dimensionale Schema soll also eintheoretisches Fundament für die Ausweitungder Betrachtung auf ein vollständiges, drei-dimensionales Schüttgutmodell liefern. Ein, aufder „open source CFD toolbox“, OpenFOAMbasierendes, vollständig drei-dimensionales,thermofluiddynamisches Modell soll im weite-ren Projektverlauf das ein-dimensionale Mo-dell ablösen und ergänzen. Durch das Heran-ziehen detaillierter, la’grangscher Methodik zurBeschreibung der drei-dimensionalen Schütt-guteigenschaften soll es gelingen die Variatio-nen zwischen verschiedenen Rohstoffqualitä-ten hochauflösend darzustellen. Damit bestün-de die Möglichkeit, einen deutlichen Fortschrittzu den bisherigen Möglichkeiten der Verga-sungsmodellierung zu erzielen.

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4.1 Light Outcoupling from Organic Light-Emitting Diodes

Contributors: C. Kirsch, R. Knaack, K. Lapagna, K. Pernstich, B. RuhstallerPartners: Glas Trösch AG, Fluxim AGFunding: CTIDuration: 2012–2014

Solid state lighting is an interesting field of appli-cation for organic light-emitting diodes (OLEDs),in addition to their more prominent use in digitaldisplays of mobile phones or televisions. Large-area flat panel lights with homogeneous lumi-nance can be produced using OLEDs. WhiteOLEDs are of particular interest in general-purpose lighting applications, as they can pro-duce warm white light that is more pleasing tothe human eye than the light from fluorescentlight sources. Because of the organic materi-als used, OLEDs are easier to dispose of thanfluorescent lamps, which contain phosphor andmercury.The luminous efficacy is an important quantityfor judging the energy efficiency of light sources:it is the ratio between the total luminous fluxemitted by the device and the total amount ofinput power it consumes. Current white OLEDdevices have a luminous efficacy similar to flu-orescent lamps and are catching up with (inor-ganic) LEDs.The organic materials used in OLED deviceshave a refractive index of n1 ' 1.7, and thelight emitted from the device needs to propa-gate into air with refractive index n2 ' 1 in atypical lighting application. The contrast in re-fractive indices causes total internal reflectionof light beyond the critical incidence angle θc

(Fig. 1), which considerably reduces the lumi-nous flux from an OLED device and thus its en-ergy efficiency. Techniques for light outcouplingimprovement include scattering foils and otherhigh-index scattering layers.In this project we are interested in the designof light outcoupling layers which can be coatedon the large-area float glass produced by GlasTrösch AG, and then be marketed to OLEDmanufacturers. At another research institute,techniques are developed to produce those lay-ers, and both partners rely on the simulation re-sults obtained by the ICP to assess the useful-ness of various light outcoupling strategies.Both geometrical optics and wave optics meth-ods are applied in this project to simulate thepropagation of light from the OLED through thelight outcoupling layer and the glass substrateinto air: Mie scattering theory is used in a com-mercial raytracing software, and scalar scatter-ing theory is used in the OLED and solar cell

simulation software Setfos by Fluxim AG. Herewe focus on wave optics.

Fig. 1: Total internal reflection for incidence angleslarger than the critical angle θc = arcsin(n2/n1).

Our simulation approach is based on rigor-ous coupled wave analysis (RCWA). This isa Fourier-space method for solving Maxwell’sequations in the frequency domain, and it canbe used to simulate the propagation of light inmedia with feature sizes on the order of thewavelength of light. RCWA does not involveany geometrical optics approximation and there-fore diffraction and interference are naturally ac-counted for. Moreover, being a semi-analyticalmethod it can be much more computationally ef-ficient than mesh-based methods.The reflection and transmission properties oflight outcoupling layers for white OLEDs mustbe non-dispersive, because otherwise the colorof the light emitted from the device would de-pend on the viewing angle. Simulations need tobe carried out over a range of wavelengths in or-der to verify this property for a given microstruc-ture. With our RCWA simulation we were able toshed light on the dispersion issue and we nowhave a better idea of the kind of microstructuresthat can be expected to be non-dispersive.Simultaneously, prototype OLED devices areproduced and experimental investigations ofvarious light outcoupling strategies conductedat ICP’s own optoelectronic research laboratory.These experimental results are also used to val-idate the simulations.

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4.2 From Atoms to Large-Area OLEDs -the IM3OLED Project

Contributors: E. Knapp, K. Lapagna, B. RuhstallerPartners: Holst Centre (Nl), Philips (Nl), Fluxim AG, Moscow Engineering Physics Insti-

tute (Ru), Kintech Lab (Ru), Photochemistry Center of the Russian Academyof Sciences (Ru)

Funding: EU-FP7Duration: 2011–2014

OLED technology provides an environmentallyfriendly technology that requires no mercuryand can potentially enable energy savings upto 90 % (per lamp socket). Global transitionto such efficient lighting sources would dramat-ically reduce the energy consumption. Sincethe onset of the solid state lighting initiative to-wards the end of the last century, the advancein OLED technology has been accelerated by aworld-wide investment in material science, pro-cess technology, and infrastructure. The tech-nological hurdles are still challenging and nu-merous, and the target efficiency, colour, colourrendering and lifetime has only partly been ac-complished.To tackle these issues the IM3OLED project (In-tegrated Multidisciplinary and Multiscale Model-ing for Organic Light-Emitting Diodes) started in2011. It is funded by the EU and is a collabo-ration between Russia and Europe. The over-all goal of the IM3OLED project is the develop-ment, evaluation and validation of a predictivemulti-scale and multi-disciplinary modelling toolthat will accelerate research and developmentof organic light-emitting diodes for lighting ap-plications. In Fig. 1 shows the tool chain fromthe molecular level up to the 3D OLED, wheresimulations and experiments on different lengthscales are performed. The focus of the ICP ison the development and refinement of the con-tinuum drift-diffusion model for organic semicon-ductors as well as on the electro-thermal large-area OLED model.

Fig. 1.: Simulation chain from the atom up to the 3D

device. The ICP develops electrical simulations aswell as 3D large-area OLEDs.

The ICP has developed an efficient large-areaOLED model based on a finite element ap-proach. The results are shown in Fig. 2, wherethe brightness of two OLEDs is compared. Dueto the low conductivity of the transparent anode,a potential drop over the device takes place re-sulting in a reduced brightness as displayed onthe left. On the right, an improved OLED with ametal grid structure to enhance the conductivityof the anode is shown.

OLED with metal gridreference OLED

Fig. 2.: Brightness distribution for a reference OLEDand an OLED with enhanced anode conductivity dueto a metal grid structure.

Further improvements can be achieved in thelight outcoupling of an OLED by introducing lay-ers that contain microstructures such as scat-ter particles or micro lenses, which support theextraction of waveguided and plasmonic modesinto the substrate and also contribute to the ex-traction from the substrate into air. These layerscan be partially modelled by means of geomet-rical optics. Therefore, the ICP has developed,in close collaboration with Fluxim, a model thatcombines the benefits of a semi-analytical de-scription of dipole emission into such layers with3D ray tracing capabilities.

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4.3 Erweiterung der Laborinfrastruktur zur Herstellung von Or-ganischen Leuchtdioden am ICP

Contributors: K. Pernstich, B. Ruhstaller, T. BeierleinPartners: keineFunding: SoE-ZHAWDuration: fortlaufend

Am ICP wird seit ca. 10 Jahren Forschungauf dem Gebiet der organischen Elektronik aufnationaler und internationaler Ebene betrieben,bisher ausschliesslich mit Modellbildung, Sim-ulation und Messtechnik. Das ICP hat diesesJahr seine Laborinfrastruktur um eine Beschich-tungsanlage für kohlenstoffbasierte Halbleitererweitert. Diese Anlage bietet insbesondere dieMöglichkeit, organische Leuchtdioden (OLEDs),aber auch organische Solarzellen und an-dere elektronische Bauteile auf Polymer-Basisherzustellen.Organische Leuchtdioden werden bereits in Dis-plays kommerziell eingesetzt, z.B. im Smart-phone Galaxy S3 von Samsung. Der Ein-satz von OLEDs als grossflächige Beleuch-tungselemente ist ebenfalls sehr vielver-sprechend. Solch grossflächige OLEDs benöti-gen keinen Lampenschirm wie konventionelleLeuchtmittel, sie sind sozusagen der Lamp-enschirm. Dadurch eröffnen sich ganz neueEinsatzmöglichkeiten, z.B. in der Architekturals transparente OLEDs integriert in eine Fen-sterscheibe, als Hintergrundbeleuchtung fürFlüssigkristallanzeigen, oder als Stilelement inRaumgestaltungen. OLEDs haben zudem imLabormassstab bereits eine höhere Effizienzals konventionelle Leuchtstofflampen bewiesen

und können so einen Beitrag zur Energieef-fizienz liefern.

Die neu angeschaffte Beschichtungsanlagebesteht aus einer mit Stickstoff gefüllten Hand-schuhbox mit angeschlossener Vakuumkam-mer. In der Handschuhbox werden die Poly-merfilme unter Ausschluss von Wasserdampfund Sauerstoff hergestellt, und in der Vaku-umkammer werden die benötigten Metallelek-troden aufgedampft. Die elektrischen und optis-chen Eigenschaften der so hergestellten Probenkönnen nun messtechnisch untersucht werdenund dienen als Grundlage zur Verifikation undErweiterung von numerischen Modellen.

Die Möglichkeiten, die diese Beschichtungsan-lage eröffnet, sind wichtig für Projekte mit Indus-triepartnern, in denen die durchgeführten Simu-lationen nun auch experimentell überprüft unddadurch auch verfeinert werden können. Ein er-stes KTI-Projekt, in dem die Anlage zum Einsatzkam, ist auf Seite 30 beschrieben. Des weiterenbietet die Anlage die Möglichkeit, zahlreichestudentische Arbeiten durchzuführen. DieseArbeiten sind trotz ihres Praxisbezugs relativnahe an der Grundlagenforschung und daherinsbesondere für Studierende in Masterstudi-engängen interessant.

Fotographie der neuen Beschichtungsanlage am ICP (links) und OLED Demonstrator der Firma Novaled(rechts).

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Appendix

A.1 Student Projects

D. BENZ, N. HÄNI, ICE-LED Video Multi-Cluster mit Redundanz, Betreuer: N. Reinke, A. Bariska,Bachelorarbeit.

B. BIGLER, F. MATHYS, Early-stage skin cancer detection with active thermography, Betreuer:M. Bonmarin, N. Reinke, A. Bariska, Bachelor Thesis.

B. BIGLER, F. MATHYS, Measurement System for Early Stage Skin Cancer Detection, Betreuer:N. Reinke, A. Bariska, Bachelorarbeit.

L. BRENNER, T. HUNKELER, Erstarrung von Schokolade im Kühlkanal, Betreuer: T. Hocker, O. Hoe-necke, Firmenpartner: Max Felchlin AG, Schwyz, 2012, Projektarbeit Maschinentechnik, Bachelorof Science.

P. FAHRNI, Y. WERNER, Thermische Analyse von Schoggi im Kühlkanal, Betreuer: T. Hocker,Firmenpartner: Max Felchlin AG, Schwyz, 2012, Bachelor Thesis Systemtechnik, Bachelor of Sci-ence.

D. GÜRTLER, Nachhaltigkeit der Brennstoffzellentechnologie in der Mini-Kraft-Wärmekoppelung,Betreuer: T. Hocker, H. Spiess, Firmenpartner: Hexis AG, Winterthur, 2012, Projektarbeit Maschi-nentechnik, Bachelor of Science.

L. KAUFMANN, Thermo-mechanisches Verhalten von Hochtemperatur-Brennstoffzellen, Betreuer:T. Hocker, Firmenpartner: Hexis AG, Winterthur, 2012, Vertiefungsarbeit Master of Science.

P. LENHERR, D. WILD, Thermogradientenprüfstand für Brennstoffzellen, Betreuer: L. Kaufmann,T. Hocker, Firmenpartner: Hexis AG, Winterthur, 2012, Bachelor Thesis Maschinentechnik, Bach-elor of Science.

D. MINDER, S. OBRADOVIC, Erstarrung von Schokolade im Labor, Betreuer: T. Hocker, O. Hoe-necke, Firmenpartner: Max Felchlin AG, Schwyz, 2012, Projektarbeit Maschinentechnik, Bachelorof Science.

D. SCHMIDBAUER, M. TORRONI, Bilderkennung in Thermografie-Bildern, Betreuer: N. Reinke,A. Bariska, Bachelorarbeit.

A. SIBILIA, Konstruktion und Herstellung eines Probenhalters für Vakuumbeschichtungen, Be-treuer: K.P. Pernstich, B. Ruhstaller, Vertiefungsarbeit Master of Science.

M. SUTER, Modeling the Shukoff Cooling Curve of Oils, Betreuer: T. Hocker, Firmenpartner: MaxFelchlin AG, Schwyz, 2012, Vertiefungsarbeit Master of Science.

E. TINNER, R. ANGEHRN, Zerstörungsfreie und berührungslose Prüfung von Verbundmaterialien,Betreuer: N. Reinke, A. Bariska, Bachelorarbeit.

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M. WERNER, M. WYSS, Skin cancer detection with active thermography, Betreuer: M. Bonmarin,N. Reinke, A. Bariska, Firmenpartner: Winterthur Instruments AG, Winterthur, Bachelor Thesis.

P. WETTER, A. KÜNZLER|, Bildgebendes Analyseverfahren für Feuchtigkeit in Bauwerken, Be-treuer: N. Reinke, A. Bariska, Bachelorarbeit.

A.2 Scientific Publications

M. BONMARIN, N. REINKE, A. FASTRICH, Vorrichtung und Verfahren zur Charakterisierung vonGewebe, Patent CH, Application Nr. 01684/12, Submitted.

D. BURNAT, A. HEEL, L. HOLZER, D. KATA, J. LIS, T. GRAULE, Synthesis and Performance ofA-Site Deficient Lanthanum-Doped Strontium Titanate by Nanoparticle Based Spray Pyrolysis, J.Power Sources, 201, 26–36, 2012.

D. BURNAT, A. HEEL, L. HOLZER, E.H. OTAL, D. KATA, T. GRAULE, On the chemical interactionof nanoscale lanthanum doped strontium titanates with common scandium and yttrium stabilizedelectrolyte materials, Int. J. Hydrogen Energy, 37, 18326–18341, 2012.

A. EVANS, M. PRESTAT, R. TÖLKE, M. V. F. SCHLUPP, L. J. GAUCKLER, Y. SAFA, T. HOCKER,J. COURBAT, D. BRIAND, N. F. DE ROOIJ, D. COURTY, Residual Stress and Buckling Patterns ofFree-standing Yttria-stabilized-zirconia Membranes Fabricatedby Pulsed Laser Deposition, FuelCells, 12, 614–623, 2012.

I. GRUBER, I. ZINOVIK, L. HOLZER, A. FLISCH, L. POULIKAKOS, A computational study of the ef-fect of structural anisotropy of porous asphalt on hydraulic conductivity, Construction and BuildingMaterials 96, 66–77, 2012.

B. IWANSCHITZ, L. HOLZER, A. MAI, M. SCHÜTZE, Nickel agglomeration in solid oxide fuel cells:the influence of temperature, Solid State Ionics, 211, 69–73, 2012.

E. KNAPP, B. RUHSTALLER, The role of shallow traps in dynamic characterization of organic semi-conductor devices , J. Appl. Phys. 112, 024519, 2012.

T. LANZ, L. FANG, S.J. BAIK, K.S. LIM, B. RUHSTALLER, Photocurrent increase in amorphousSi solar cells by increased reflectivity of LiF/Al electrodes, Solar Energy Materials and Solar Cells107, 25, 2012.

CH. MEIER, T. HOCKER, A. BIEBERLE-HÜTTER, L. J. GAUCKLER, Analyzing a micro-solid oxidefuel cell system by global energy balances, Int. J. Hydrogen Energy, 37 (13), 10318–10327, 2012.

A. NAKAJO, J. KUEBLER, A. FAES, U. VOGT, H. SCHINDLER, L. CHIANG, S. MODENA, J. VAN HER-LE, T. HOCKER, Compilation of mechanical properties for the structural analysis of solid oxide fuelcell stacks. Constitutive materials of anode-supported cells, Ceramics International, 38, 3907–3927, 2012.

M.T. NEUKOM, S. ZÜFLE, B. RUHSTALLER, Reliable extraction of organic solar cell parameters bycombining steady-state and transient techniques, Organic Electronics 13, 2012.

B. PERUCCO, N.A. REINKE, D. REZZONICO, E. KNAPP, S. HARKEMA, B. RUHSTALLER, On theexciton profile in OLEDs-seamless optical and electrical modeling, Organic Electronics 13, 2012.

N. REINKE, Pulverschichtdicken dank innovativer Autokalibration präzise messen, Besser lack-ieren, Juli 2012.

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N. REINKE, Feuchte Lacke auf Kunststoff messen, JOT Journal für Oberflächentechnik, Juni 2012.

J.O. SCHUMACHER, J. ELLER, G. SARTORIS, B. SEYFANG , T. COLINART, A 2+1D model of aproton exchange membrane fuel cell with glassy-carbon micro-structures, Mathematical and Com-puter Modelling of Dynamical Systems, 1–23, 2012.

D. WIEDENMANN, L. KELLER, L. HOLZER, J. STOJADINOVIC, B. MÜNCH, L. SUAREZ, B. FUMEY,H. HAGENDORFER, R. BRÖNNIMANN, P. MODREGGER, M. GORBAR, U. VOGT, A. ZÜTTEL, F. LA-MANTIA, R. WEPF, B. GROBÉTY, 3D pore structure and ion conductivity of porous ceramic di-aphragms, AIChE Journal, in press, 2012.

A.3 Book Chapters

L. HOLZER, M. CANTONI, Nanofabrication using focused ion and electron beams: Principles andapplications, Book Chapter, Review of FIB-tomography / I. Utke, S.A. Moshkalev, Ph. Russell (Ed.)- Oxford University Press, NY, USA, ISBN 9780199734214, 410–435, 2012.

A.4 News Articles

EMPA, Turbo für die Brennstoffzelle, Seite 27, c’t 2/2013.

N. WEIBEL, ZHAW entwickelt Computermodelle – lang lebe die Brennstoffzelle, UnternehmerZeitung.

A.5 Exhibitions

M. Bonmarin, Lock-In Thermography, World Medtech Forum, Lucerne, 2012.

M. Prestat et al. Miniaturized free-standing SOFC membranes on silicon chips. In: 10th EURO-PEAN SOFC FORUM, Lucerne, 2012.

A.6 Conferences and Workshops

S. BAIK, M. NEUKOM, L. FANG, K. LIM, T. VAN DER HOFSTAD, T. LANZ, B. RUHSTALLER, Fast anddirect characterization of thin film Si solar cells using CELIV, 27th European Photovoltaic SolarEnergy Conference and Exhibition, Frankfurt, Germany, 2012.

P. CENDULA, M. SCHMID, J. O. SCHUMACHER, Development of a comprehensive numerical modelof a solar water splitting cell, International Conference on Nanostructured Systems for Solar FuelProduction, Mallorca, Spain, 2012.

A. EVANS ET AL., Residual stress and buckling patterns of yttria-stabilisedzirconia thin films formicro-solid oxide fuel cell membranes, The Electrochemical Society, 221st ECS Meeting, Wash-ington, USA, 2012.

L. HOLZER, M. CANTONI, PH. GASSER, B. MÜNCH, L. KELLER, FIB-tomography: Review anddiscussion of applications in materials science, Interdisciplinary symposium on 3D-microscopy,

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SSOM, Les Diablerets, 2012.

L. HOLZER, TH. HOCKER, L. KELLER, M. PRESTAT ET AL., Quantitative tomography for the pre-diction of transport kinetics in SOFC electrodes and in porous diaphragms for electroysis cells,E-MRS Spring Meeting, Strasbourg, France, 2012.

B. IWANSCHITZ, L. HOLZER, A. MAI, M. SCHÜTZE, Nickel agglomeration in solid Oxide Fuel Cellsunder different operating conditions, 10th European Fuel Cell Forum EFCF, A1001, Lucerne, 2012.

B. IWANSCHITZ, L. HOLZER, A. MAI, M. SCHÜTZE, Nickel agglomeration in solid Oxide FuelCells under different operating conditions, Jahrestreffen Fachgruppen Energieverfahrenstechnikund Hochtemperaturtechnik, DECHEMA, Frankfurt, Germany, 2012.

Y. JAMASHITA, B. RUHSTALLER, Advanced Characterization of Solar Cells, Swiss Green Technolo-gies Seminar, Tokyo, Japan, 2012.

L. KELLER, L. HOLZER, Imaging methods and its use in characterizing the pore space of OpalinusClay in 3D, Int. Clay Conference, Montpelier, France, 2012.

E. KNAPP, The Role of Shallow Traps in Dynamic Characterization of Organic Semiconductor De-vices, SIMOEP 12, Olvia, Spain, 2012.

T. LANZ, C. BATTAGLIA, C. BALLIF, B. RUHSTALLER, Model-based Quantitative Assessment ofCrystallinity and Parasitic Absorption in Microcrystalline Silicon Solar Cells, Spring MRS, San Fran-cisco, USA, 2012.

M. NEUMANN, G. GAISELMANN, A. SPETTL, L. HOLZER, T. HOCKER, M. PRESTAT, V. SCHMIDT,Structural Segmentation and Stochastic 3D modeling of La0.6Sr0.4CoO3-d - cathodes, 9th Sym-posium on Fuel Cell and Battery Modeling and Experimental Validation Modval, Sursee, 2012.

O. PECHO, L. HOLZER, Z. YANG, TH. HOCKER, R. FLATT, J. MARTINZUK, L. GAUCKLER, M. PRE-STAT, Quantitative microstructure analysis and electrochemical activity of La0.6Sr0.4CoO3-d elec-trodes deposited by spray pyrolysis, Materials Research Fall Meeting MRS, Boston, USA, 2012.

O. PECHO, M. PRESTAT, Z. YANG, J.H. HWANG, J.W. SON, L. HOLZER, T. HOCKER, J. MAR-TYNCZUK, L. GAUCKLER, Microstructural and electrochemical characterization of thin La0.6Sr0.-4CoO3-d cathodes deposited by spray pyrolysis, 10th European Fuel Cell Forum EFCF, B04-61,Lucerne, 2012.

O. PECHO, M. PRESTAT, Z. YÁNG, L. HOLZER, T. HOCKER, J. MARTYNCZUK, L. GAUCKLER,Quantitative microstructure analysis and electrochemical activity of La0.6Sr0.4CoO3-d electrodesdeposited by spray pyrolysis, CFN Summer School on Nano-Energy, Poster, Bad Herrenalb, Ger-many, 2012.

M. PRESTAT, A. EVANS, R. TÖLKE, M.V.F. SCHLUPP, B. SCHERRER, Z. YANG, J. MARTYNCZUK,O. PECHO, H. MA, A. BIEBERLE-HUTTER, L. GAUCKLER, Y. SAFA, T. HOCKER, L. HOLZER,P. MURALT, Y. YAN, J. COURBAT, D. BRIAND, N.F. DEROOIJ, Miniaturized free-standing SOFCmembranes on silicon chips, 10th European Fuel Cell Forum EFCF, A07-30, Lucerne, 2012.

M. PRESTAT, L. HOLZER, T. HOCKER, O. PECHO, ET AL., Miniaturized solid oxide fuel cells ona chip, 9th Symposium on Fuel Cell and Battery Modeling and Experimental Validation Modval,Sursee, 2012.

M. PRESTAT, Z. YÁNG, O. PECHO, L. HOLZER, J. MARTYNCZUK, A. EVANS, L. GAUCKLER,T. HOCKER, J. HWANG, J. SON, Nanostructured La0.6Sr0.4CoO3-d Cathodes Prepared by SprayPyrolysis for Thin Film SOFC, Pacific Rim Meeting on electrochem. and solid-state science / 222nd

36 ZHAW


meeting of ECS, PRIME2012, Honolulu, USA, 2012.

N. REINKE, Thermische Schichtprüfung, Zentralschweizer Photonenmesstag - floir ag, Gisikon-Root, 2012.

N. REINKE, Berührungslose Prüfung von Materialien und Oberflächen, Thüringer Grenz- undOberflächentag, Leipzig, Germany, 2012.

N. REINKE, Berührungslose Prüfung von Materialien und Oberflächen, Winterthurer Oberflächen-tag, Winterthur, 2012.

N. REINKE, Feuchte Lacke auf Kunststoff messen, Fachtagung Oberflächentechnik, Kunststoff-Institut Lüdenscheid, Germany, 2012.

N. REINKE, Bildgebende Analyseverfahren für Mauerwerk, Tagung Einblick in Beton, Irscat AG,Oberdorf, 2012.

B. RUHSTALLER, Advanced simulation of OLEDs and organic solar cells, Keynote Lecture at theWinter School of Organic Electronics, Universität Heidelberg, Heidelberg, Germany, 2012.

B. RUHSTALLER, Charge Transport and Light Propagation in Organic Semiconductor Devices, Intl.Conference on Simulation of Organic Electronics and Photovoltaics (SIMOEP), Oliva, Spain, 2012.

B. RUHSTALLER, Charge Transport and Light Propagation Modeling in Organic Semiconductor De-vices, Jahrestagung der Schweizerischen Physikalischen Gesellschaft (SPG), Zürich, 2012.

Y. SAFA ET AL., A Validated Model of Membrane Mechanics for Micro SOFC, 9th Symposium onFuel Cell and Battery Modelling and Experimental Validation, PSI Paul Scherrer Institut, 2012.

J.A. SCHULER, B. IWANSCHITZ, L. HOLZER, M. CANTONI, TH. GRAULE, Stroboscopic Ni Growth/-Volatilization Picture, 10th European Fuel Cell Forum EFCF, B0501, Lucerne, 2012.

J.O. SCHUMACHER, B. PERUCCO, FELIX N. BÜCHI, J. ROTH, Sensitivity analysis and investiga-tion of parameter interactions of a model of the membrane electrode assembly of a PEM fuel cell,9th Symposium on Fuel Cell and Battery Modeling and Experimental Validation, Campus Sursee,2012.

A.7 Prizes and Awards

E. Tinner and R. Angehrn received the Axa Innovationspreis for their Bachelor Thesis Zerstörungs-freie und berührungslose Prüfung von Verbundmaterialien.

N. Reinke and A. Bariska received the 2nd Rank Prix Strategis Award for their Spin-Off CompanyWinterthur Instruments AG.

N. Reinke and A. Bariska received the 2nd Rank Swisspark Start-up of the year for their Spin-OffCompany Winterthur Instruments AG.

N. Reinke and A. Bariska received the besser lackieren! Produkthighlight Award for their Spin-OffCompany Winterthur Instruments AG.

N. Reinke and A. Bariska received the Heuberger Jungunternehmerpreis for their Spin-Off Com-pany Winterthur Instruments AG.

37 ZHAW


N. Reinke and A. Bariska received the Swiss Top 100 Entrepreneurs Award for their Spin-Off Com-pany Winterthur Instruments AG.

P. Fahrni and Y. Werner received the 3. Price in Life Sciences of the Veronika und Hugo BohnyStiftung und Toolpoint Cluster for their Bachelor Thesis Thermische Analyse von Schoggi im Küh-lkanal .

P. Wetter and A. Künzler received the Siemens Excellence Award for their Bachelor Thesis Bild-gebendes Analyseverfahren für Feuchtigkeit in Bauwerken.

A.8 Teaching

M. BONMARIN, Physik für Ingenieure 1, Bachelor of Science.

J.O. SCHUMACHER, Physik für Ingenieure 1, Bachelor of Science.

N. REINKE, Physik für Ingenieure 1, Bachelor of Science.

N. REINKE, Physik für Maschinentechnik 2, Bachelor of Science.

J.O. SCHUMACHER, Physik für Maschinentechnik 2, Bachelor of Science.

N. REINKE, Physik für Systemtechnik 2, Bachelor of Science.

T. HOCKER, Physik und Systemwissenschaft für Aviatik 1, Bachelor of Science.

T. HOCKER, Fluid- und Thermodynamik 1, Bachelor of Science.

T. HOCKER, Fluid- und Thermodynamik 3, Bachelor of Science.

B. RUHSTALLER, Grundlagen der Solartechnik, Bachelor of Science.

B. RUHSTALLER, Messtechnik in Solarsystemen, Bachelor of Science.

T. HOCKER, Mensch–Technik–Umwelt, Bachelor of Science.

N. REINKE, Sensorik Praktikum, Bachelor of Science.

R. AXTHELM, Mathematik für Ingenieure 1, Bachelor of Science.

R. AXTHELM, Mathematik für Ingenieure 2, Bachelor of Science.

R. AXTHELM, Mathematik: lineare Algebra für Ingenieure 1, Bachelor of Science.

M. SCHMID, Mathematik: lineare Algebra für Ingenieure 1, Bachelor of Science.

R. AXTHELM, Mathematik: lineare Algebra für Ingenieure 2, Bachelor of Science.

M. SCHMID, Mathematik: lineare Algebra für Ingenieure 2, Bachelor of Science.

C. KIRSCH, Natur, Technik und Systeme 1 – Praktikum, Bachelor of Science.

T. HOCKER, Heat and mass transfer with two-phase flow, Master of Science.

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J.O. SCHUMACHER, Advanced Thermodynamics, Master of Science in Engineering.

J.O. SCHUMACHER, Multiphysics Modelling and Simulation, Master of Science in Engineering.

J.O. SCHUMACHER, Mathematical Methods, Master Online Photovoltaics, Germany.

J.O. SCHUMACHER, Numerical Simulation of Solar Cells, Master Online Photovoltaics, Germany.

G. SARTORIS, Masterprogram Micro- and Nanotechnology MNT, Weiterbildung.

39 ZHAW


A.9 ICP-TeamName Function e-Mail

Dr. Rebekka Axthelm Lecturer [email protected]. Gernot Boiger Lecturer [email protected]. Mathias Bonmarin Research Associate [email protected]. Peter Cendula Research Associate [email protected] Hauri Research Assistant [email protected]. Dr. Thomas Hocker Lecturer, Head ICP [email protected]. Lorenz Holzer Research Associate [email protected] Kaufmann Research Assistant [email protected]. Lukas Keller Research Associate [email protected]. Christoph Kirsch Research Associate [email protected] Knapp Research Associate [email protected] Lanz Research Assistant [email protected] Lapagna Research Assistant [email protected] Linder Research Assistant [email protected] Meier Research Assistant [email protected] Pecho Research Associate [email protected]. Kurt Pernstich Research Associate [email protected]. Nils Reinke Lecturer [email protected] Ritzmann Research Assistant [email protected]. Dr. Beat Ruhstaller Lecturer [email protected]. Yasser Safa Research Associate [email protected]. Guido Sartoris Research Associate [email protected] Schmid Research Assistant [email protected]. Matthias Schmid Lecturer [email protected]. Dr. Jürgen Schumacher Lecturer [email protected] Spiess Administrative Assistant [email protected] Toniolo Administrative Assistant [email protected]

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mailto:[email protected]




























A.10 Spin-off Companies

www.nmtec.ch

Numerical Modelling GmbH works in the field of Computer Aided Engineering (CAE) and offersservices and simulation tools for small and medium enterprises. Our core competence is knowl-edge transfer: we bridge the gap between scientific know-how and its application in the industry.With our knowledge from physics, chemistry and the engineering sciences we are able to pro-foundly support your product development cycle. Numerical Modelling speaks your language andis able to conform to given constraints with respect to time and budget.We often create so-called customer specific CAE tools in which the scientific knowledge requiredfor your product is embedded. In this form, it is easily deployed within your R&D departmentand supports actual projects as well as improving the skills of your staff. Ask for our individualconsulting service which covers all areas of scientific knowledge transfer without obligation.

www.fluxim.com

FLUXiM AG is a provider of device simulation software to the display, lighting, photovoltaics andelectronics industries worldwide. Our principal activity is the development and the marketing of thesimulation software SETFOS which was designed to simulate light emission from thin film devicessuch as organic light-emitting diodes (OLEDs), thin film solar cells (organic and inorganic) andorganic semiconducting multilayer systems.Our company name FLUXiM is derived from flux simulation. Our software products are usedworldwide in industrial and academic research labs for the study of device physics and productdevelopment. Check out our references and testimonials for more info. We develop swiss-madesoftware in Switzerland and in addition also provide services such as consulting, training andsoftware development, see our services page for more details.

www.winterthurinstruments.ch

Winterthur Instruments AG develops measurement systems for fast non contact and non destruc-tive testing of industrial coatings. These measurement systems can be used to determine coatingthicknesses, material parameters (e.g. porosity) and contact quality (e.g. to detect delamination).The system is based on optical-thermal measurements and works with all types of coating andsubstrate materials. Our measurement systems provide the unique opportunity of non-contact andnon-destructive testing of arbitrary coatings on substrates.

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http://www.nmtec.ch/

http://www.fluxim.com/

http://www.winterthurinstruments.ch/

A.11 Location

ICP Institute ofComputational Physics

Technikumstrasse 9P.O. BoxCH-8401 Winterthur

www.icp.zhaw.ch

ContactThomas HockerPhone +41 58 934 78 [email protected]

AdministrationLilian TonioloPhone +41 58 934 73 [email protected]

TK-Building TL-Building

www.icp.zhaw.ch



http://map.search.ch/winterthur/wildbachstr.21

Zurich University

of Applied Sciences

School ofEngineering

ICP Institute ofComputational Physics

Technikumstrasse 9

P.O. Box

CH-8401 Winterthur

Phone +41 58 934 71 71

[email protected]

www.icp.zhaw.ch

Documents

ZHAW ICP Research Report 2012