Events Archive

We live in an increasingly hyper-connected environment where humans, smart devices and robots live in synergy together. Flexible, wearable sensors and systems are accelerating this trend by generating ever greater amounts of data for AI algorithms to process and understand. Exciting developments in bio-integrable and neuro-integrable sensory systems will further augment human abilities and aid in applications as health diagnostics, surgery and predictive analytics.
We believe a multi-disciplinary approach especially in materials design and processing is essential to achieve near or even superhuman capabilities in robotics. In the area of manipulation tasks, robots have yet to match human abilities despite progress in various sensing and actuator systems. We apply a neuromorphic approach for sensory systems as a potential pathway towards greater tactile and machine intelligence. I will discuss our approach and recent progress in developing new soft materials systems and bio-mimetic approaches for robotic intelligence. Fusion of sensing modalities such as neuromorphic vision and touch will also facilitate robotic learning towards greater autonomy, especially as remote work, and “digitial twins” gains critical importance in pandemics and the future of work

Dr. Benjamin C.K. Tee is appointed President’s Assistant Professor in Materials Science and Engineering Department at the National University of Singapore. His leads his research group: Sensors.AI to develop technologies at the cutting edge of materials science, mechanics, electronics and biology, with a focus on sensitive electronic materials that has tremendous potential to advance global healthcare technologies in an increasingly Artificial Intelligence (AI) era. He was awarded the National Research Foundation Fellowship in 2017. He obtained his PhD at Stanford University, and was a Singapore-Stanford Biodesign Global Innovation Postdoctoral Fellow in 2014. He is an MIT TR35 Innovator (Global) in 2015 and listed as World Economic Forum’s Young Scientist of the year in 2019. He was featured by CNN International as one of their Tomorrow’s Hero series, by Channel News Asia International in the ASEAN’s Next Generation Leaders documentary and by BBC World Service Radio and National Geographic TV. He can be found on https://www.benjamintee.com.

Robotics and artificial intelligence (AI) hold the key to Industry 4.0. To stay relevant in the AI age, humans must collaborate and/or even merge with human-centered robotics to enable internet of health (IoH), augmented reality (AR), as well as augmented human capabilities. However, bio-tissues are soft, curvilinear and dynamic whereas conventional machines and electronics are hard, planar, and rigid. Over the past decade, soft electronics blossom as a result of new materials, novel structural designs, and freeform manufacturing processes. This talk will discuss our research in the design, fabrication, conformability, and functionality of soft bio-integrated and bio-mimetic electronics based on inorganic functional materials such as metals, silicon, carbon nanotubes (CNT), and graphene. In particular, epidermal electronics, a.k.a. electronic tattoos (e-tattoos) represent a class of noninvasive stretchable circuits, sensors, and stimulators that are ultrathin, ultrasoft and skin-conformable. My group has invented a dry and freeform “cut-solder-paste” method for the rapid prototyping of multimodal, wireless, or very large area stretchable e-tattoos. The e-tattoos can be applied for physiological sensing, prosthesis, and human-mimetic robots. Examples could range from human-robot interaction to implantable artificial retina. A perspective on future opportunities and challenges in this field will be offered at the end of the talk.

Dr. Nanshu Lu is currently Temple Foundation Endowed Associate Professor at the University of Texas at Austin. She received her B.Eng. from Tsinghua University, Beijing, Ph.D. from Harvard University, and then Beckman Postdoctoral Fellowship at UIUC. Her research concerns the mechanics, materials, manufacture, and human integration of soft electronics. She has been named 35 innovators under 35 by MIT Technology Review. She has received US NSF CAREER Award, US ONR and AFOSR Young Investigator Awards, 3M non-tenured faculty award, and iCANX/ACS Nano Inaugural Rising Star Lectureship. She has been selected as one of the five great innovators on campus and five world-changing women at UT Austin. She is named a highly cited researcher by Web of Science.

Auf der gesetzlichen Grundlage der Vereinigung der Kantonalen Feuerversicherungen (VKF) hat die Schulleitung der Abteilung Betrieb den Auftrag erteilt, periodisch (alle 4 Jahre) integrale Tests an den haustechnischen Anlagen durchzuführen.

Auf dieser Grundlage erfolgte der letzte integrale Test am 12. Januar 2017, der nächste ist auf das Datum 14.1.2021 gesetzt.

On the legal basis of the Association of the Cantonal Fire Insurers (VKF), the Executive Board of the Operations Department has placed an order to carry out periodic integral tests on the service installations system in the building.

On this basis, the last integral test took place on 12 January 2017, the next is set for the date 14.1.2021.

Ziel: Sicherstellung der Personensicherheit, Sachschutz und Betriebssicherheit im HCI-Gebäude.
Goal: Ensure personal safety, property protection, and operational safety in the HCI building.

Es werden an diesem Tag zwei Testszenarien durchgeführt:
1. Totalausfall Stromversorgung mit anschliessendem Notstrombetrieb
2. Brandfall in den einzelnen Gebäudeteilen

Two test scenarios will be carried out:
1. Total power outage followed by emergency power supply.
2. Fire drill in various parts of the building.

Konsequenzen für die Nutzer / Consequences for users:

Die detaillierten Abläufe werden noch kommuniziert / The detailed procedures are still being communicated.

Kontaktstelle für Rückfragen / Contact for queries: chab-safety@chem.ethz.ch

Soft robots have the potential to be more robust, adaptable, and safer for human interaction than traditional rigid robots. State-of-the-art developments push these soft robotic systems towards applications such as rehabilitation and diagnostic devices, exoskeletons for gait assistance, and grippers that can handle delicate objects. However, despite these exciting developments, there are two major challenges: (1) existing electronic control, intelligence and power of soft robots is too bulky to be embedded, and (2) the power efficiency of soft robots is extremely low. As a result, most existing soft robots still rely on tethers to deliver the required power and control.

To increase the application perspective of soft robots, in our group we aim to 'cut the tethers', with the ultimate goal to realize fully autonomous and smart soft robots that can interact with humans and complex environments. To do so, we aim to replace the electronics by other modes of control using only soft elements that are embedded in the fluid that drives soft fluidic actuators. As a starting point, we are focussing on elastic hysteretic valves that allow us to harness nonlinear mechanical behavior to program complex actuation patterns in multiple actuators. We analyze the dynamic behavior of these systems using the electronic-hydraulic analogy, and show that these circuits can deliver complex flows (e.g. pulsatile) to individual actuators in response to constant inflow conditions. We furthermore show that we can change the behavior of the soft system by only varying the initial conditions, such that we can potentially build soft robots that can be mechanically programmed to walk using multiple robust gaits, without the need for electronics.

Based on these results, we will continue our future efforts in this direction by developing and integrating fluidic sensors and (chemical) pressure generators. By also closing the fluidic circuits, we hope to be able to reuse elastic energy that is currently lost after each actuation cycle, in order to dramatically increase the efficiency of soft robots. Taking together, this research paves the way for the first fully autonomous soft robots that are capable of operating for longer periods of time.

CV: http://www.overvelde.com/wp-content/uploads/2017/12/JTB-Overvelde-CV-1.pdf

2D and layered materials are generating excitement due to their novel electronic, optical, thermal, and mechanical properties. Novel applications include high-performance solid lubricants due to their ability to achieve “superlubricity” (nearly zero friction), and functional materials for flexible electronics due to their exceptional bendability, strength, and electronic behavior. Yet the limits of their durability, friction, and adhesion and not understood.

To explore these limits, we study nanocontacts with 2D and layered materials including graphene and MoS2 with atomic force microscopy (AFM). First, we find that friction is intrinsically low, but depends strongly on the number of layers underneath the AFM tip, doubling in magnitude for monolayers vs. multilayers. A model attributing this to adhesion-induced “puckering” of the ultrathin 2D layers around the tip [1] is now enhanced by molecular dynamics (MD) simulations showing a strong role of the “quality” of the contact. In particular, energy barriers to sliding are affected by interfacial pinning and commensurability due to subtle deformations of the 2D material [2].

Second, we have discovered another contact quality effect in probing nanoscale sliding against graphite while varying the relative humidity. Water acts as a lubricant only above a threshold humidity; below that, adsorbed water increases friction six-fold relative to dry sliding. Such a non-monotonic dependence of friction has been previously attributed to a humidity-dependent water meniscus. We reveal a new possibility, where the number and location of water molecules at the interface controls friction [3].

Finally, unique nanocontact experiments obtained in situ using transmission electron microscopy (TEM) are used to observe tip-on-tip contact and sliding behavior for few-layer MoS2. We quantify adhesion, observing a strong role of defects which evolves with repeated contact cycles.

[1] C. Lee et al. Frictional Characteristics of Atomically-Thin Sheets. Science, 328, 76 (2010).
[2] S. Li et al. The Evolving Quality of Frictional Contact with Graphene. Nature 539, 541 (2016).
[3] Hasz, K. et al. Experiments and Simulations of the Humidity Dependence of Friction between Nanoasperities and Graphite: The Role of Interfacial Contact Quality. Phys. Rev. Mat. 2, 126001 (2018).

[1] V. Venkataramani, R. Sureshkumar, and B. Khomami. Coarse-grained modeling of macromolecular solutions using a configuration-based approach. Journal of Rheology, 52(5):1143-1177, 2008.
[2] H. C. Öttinger. On the combined use of friction matrices and dissipation potentials in thermodynamic modeling. Journal of NonEquilibrium Thermodynamics, 44(3):295-302, 2019.
[3] R. G. Larson, H. Hu, D. E. Smith, and S. Chu. Brownian dynamics simulations of a DNA molecule in an extensional flow field. Journal of Rheology, 43(2):267-304, 1999.

Colloidal dispersions of rod-like particles are widely accepted as convenient model systems to study the phase behavior of liquid-crystal forming systems, commonly found in LCDs. This is due to the fact that colloidal rods exhibit analogous phase behavior to that of elongated molecules, while they can be directly observed by optical microscopy. More recently, there has also been a burst of interest in the liquid crystalline behaviour of so-called bent-core, or banana-shaped, molecules, which have been predicted to form exotic biaxial nematic phases such as the twist-bend and splay-bent nematic phase. These may be of particular interest due to their fast switching response in LCDs. While there have been claims of the observation of these biaxial nematic phases in molecular bent-core systems, no colloidal bananas have been reported in which these the structure and dynamics of these phases could be imaged at the particle level.

Here, we have developed an entirely new family of colloidal SU-8 polymer particles, with shapes ranging from rods, sphero-cylinders, spheres and bananas with tuneable length, diameter and curvature that are stable in both aqueous and apolar solvent mixtures. Our colloidal SU-8 polymer particles are produced in bulk and by varying the composition of the solvent mixture, both the difference in refractive index and mass density between the particles and the solvent can be independently controlled. This, for example, enables the use of colloidal SU-8 rods in both 3D confocal microscopy and optical trapping experiments, and even in experiments combining both techniques, while the effect of gravity can be carefully tuned. Particularly exciting is that we can tune the curvature of the bananas, which is a key parameter in their phase behaviour. This is demonstrated by our observations of the exotic structures formed by differently curved bananas, including isotropic, anti-ferromagnetic smectic and even the elusive splay-bend nematic ordering and a completely new `colloidal vortex liquid'.

Humankind has always been fascinated by bioinspiration. In this talk, I will first highlight some examples from life in air, water, and on earth, involving bird flight, deep-sea fish, and terrestrial locomotion. An intrinsic commonality is the scaling laws which all systems have to obey. While flying objects have been shown to scale isometrically over 12 orders of magnitude in mass, we found the scaling of the length of the humerus bone in several different birds to be non-isometric (or allometric). In the dragon fish, a deep-sea predator off the coast of southern California, teeth were surprisingly found to be translucent or even transparent. Finally, from fruit flies to geckoes, locomotion is mediated by progressively finer keratinous fibrils on their adhesion organs. We have over the last decade developed an innovative robotic handling concept which has entered industrial application. It is based on the “gecko principle” with support from scaling arguments and detailed numerical modeling. The concept has recently led to the successful repair of ear drums, which closes the circle from bio-inspiration to bio-application.

Eduard Arzt is Scientific Director of INM – Leibniz Institute for New Materials in Saarbrücken, one of the leading German materials research laboratories. His research focuses on bioinspired materials and surfaces, from fundamental science to practical application. He received a PhD in physics from the University of Vienna, Austria, and was a postdoctoral researcher at Cambridge University, UK. Prior to his present position, he was director at the Max Planck Institute for Metals Research, Stuttgart, one of the leading research institutes devoted to metals and structural materials. There, he pioneered new concepts of alloys for extremely high temperatures. Arzt ist strongly connected internationally and has held various visiting appointments e.g. at Stanford, MIT and UC San Diego. He is member of two national academies and the recipient of high research awards, such as the prestigious Leibniz Award, a European ERC Advanced Grant and recently two ERC Proof-of-Concept Grants. Arzt is editor-in-chief of the leading review journal Progress in Materials Science.

In the second part I will explain my master’s thesis work: it is well known in literature that double helix DNA macromolecule cannot exhibit smectic order, due to the self-assembly nature of stack interaction. Recent developments in DNA nanotecnology and DNA origamy allow to inhibit stack interaction and allow to create double helix hairpin with smectic order. In this framework, also particles with complex shapes can be created, for example the asymmetric duplex exhibiting new exotic mesophase. I studied these macromolecules from a computational point of view, using simple coarse-grained models and Monte Carlo simulations, trying to confirm experimental results. I also developed a new protocol based on thermodynamic integration that allows to compute the difference in free energy between two smectic metastable states, and that can be easily generalized in different contexts.

Finally, I will suggest some strategies that may be used in order to study ellipsoidal particles at interfaces, like maximum entropy principle with experimental datas for empirical potential optimization.

[1] B. Leimkuhler, C. Matthews and J. Weare, Ensemble preconditiong for Markov Chain Monte Carlo simulation, Statistics and Computing, 28:277-290, 2018.
[2] A. Martinsson, J. Lu, B. Leimkuhler, and E. Vanden-Eijnden, The simulated tempering method in the infinite switch limit with adaptive weight learning, Journal of Statistical Mechanics: Theory and Experiment, 013207, 2019.
[3] Z. Trstanova, B. Leimkuhler and T. Lelievre, Local and global perspectives on diffusion maps in the analysis of molecular systems, 2019. https://arxiv.org/abs/1901.06936
[4] F. Heber, Z. Trstanova and B. Leimkuhler, TATi - Thermodynamic Analytics ToolkIt: TensorFlow-based software for posterior sampling in machine learning applications, 2019. https://arxiv.org/abs/1903.08640.

Magnetic skyrmions are topologically-nontrivial spin textures with particle-like properties [1]. Their size, topological stability, and mobility suggest their use in future generations of spintronic devices, the prototype of which is the skyrmion racetrack [2]. To realise a racetrack requires three basic operations: the nucleation (writing), propagation (manipulation), and detection (reading) of a skyrmion, all by electrical means. Here we show that all three are experimental feasible at room temperature in Pt/Co/Ir or Pt/CoB/Ir multilayers in which the different heavy metals above and below the magnetic layer break inversion symmetry and induce chirality by means of the Dzyaloshinskii-Moriya interaction, defining the structure of Néel skyrmion spin textures [3]. We show deterministic nucleation on nanosecond timescales using an electrical point contact on top of the multilayer [4], current-driven propagation along a wire in which they are channelled by defects in the multilayer, and detection by means of the Hall effect that reveals an unexpectedly large contribution to the Hall signal that correlates with the topological winding number [5].

[1] Nagaosa, N. & Tokura, Y. (2013). Topological properties and dynamics of magnetic skyrmions. Nat. Nanotech. 8, 899.
[2] Fert, A. et al. (2013). Skyrmions on the track. Nature Nanotech. 8, 152.
[3] Zeissler, K. et al. (2017). Pinning and hysteresis in the field dependent diameter evolution of skyrmions in Pt/Co/Ir superlattice stacks. Sci. Rep. 7, 15125.
[4] Finizio, S. et al., Deterministic field-free skyrmion nucleation at a nano-engineered injector device. arXiv:1902.10435.
[5] Zeissler, K, et al. (2018). Discrete Hall resistivity contribution from Néel skyrmions in multilayer nanodiscs. Nature Nanotech. 13, 1161.

Friction of hydrogel networks in aqueous solution pertains to many practical applications in the engineering and biomedical fields where they can often provide low friction. When they are used as thin coatings on rigid substrates such as glass, stress amplification associated with contact confinement results in an enhanced drainage of the hydrogel network. As a result, the contact and frictional response of hydrogel films involves a poorly understood coupling between the elastic response of the polymer network and stress-induced permeation processes.

I will review some of our recent work on the contribution to friction of poroelastic drainage of thin (less than 10 µm) hydrogel films. We carried out friction and indentation experiments using model Poly(PEGMA) (poly(ethylene glycol)) methyl ether methacrylate) or poly(DMA) (dimethylacrylamide) gel films grafted onto glass substrates by a thiol-ene click chemistry route. From friction force measurements and in situ contact observations, we show that the frictional behaviour is controlled by a Péclet number corresponding to the ratio of advective (sliding) to diffusive components (fluid drainage). The role of contact conditions (velocity, normal force, film thickness) and of the elastic and permeation properties of the gel network will be discussed in the light of the development of a poroelastic model based on a thin film approximation. The issue of phase transitions (glass transition, phase separation, …) when the film is drained below some critical water content will also be addressed.

J. Delavoipière, Y. Tran, E. Verneuil, B. Herteufeu, C.-Y. Hui and A. Chateauminois, Langmuir 34 (2018) 9617-9626
J. Delavoipière, Y. Tran, E. Verneuil and A. Chateauminois, Soft Matter 12 (2016) 8049-8058

Magnetic nanoparticles have been building blocks in applications ranging from high density recording to spintronics and nanomedicine [1]. Magnetic anisotropies in nanoparticles arising from surfaces, shapes and interfaces in hybrid structures are important in determining the functional response in various applications. In this talk I will first introduce the basic aspects of anisotropy and discuss resonant RF transverse susceptibility, that we have used extensively, as a powerful method to probe the effective anisotropy in magnetic materials. Tuning anisotropy has a direct impact on the performance of functional magnetic nanoparticles in biomedical applications such as contrast enhancement in MRI and magnetic hyperthermia cancer therapy. I will focus on the role of tuning surface and interfacial anisotropy with a goal to enhance specific absorption rate (SAR) or heating efficiency. Strategies going beyond simple spherical structures such as exchange coupled core-shell nanoparticles, nanowire, nanotube geometries can be exploited to increase heating efficiency in magnetic hyperthermia [2,3]. In addition to biomedical applications, composites of anisotropic nanoparticles dispersed in polymers pave the way to a range of electrically and magnetically tunable materials for RF and microwave device applications [4]. This lecture will combine insights into fundamental physics of magnetic nanostructures along with recent research advances in their application in nanomedicine and electromagnetic devices.

References:
[1] E.A. Périgo et al., “Fundamentals and advances in magnetic hyperthermia”, Appl. Phys. Rev. vol. 2, 041302 (2015)
[2] Z. Nemati et al., “Core-shell iron/iron oxide nanoparticles: Are they promising for magnetic hyperthermia?”, RSC Advances vol. 6, 38697 (2016)
[3] H. Khurshid et al., “Tuning exchange bias in Fe/γ-Fe2O3 core-shell nanoparticles: Impacts of interface and surface spins”, Appl. Phys. Lett. vol. 104, 072407 (2014)
[4] K. Stojak et al., “Polymer nanocomposites exhibiting magnetically tunable microwave properties”, Nanotechnology vol. 22, 135602 (2011)

Biography
Hari Srikanth is a Professor of Physics at the University of South Florida in Tampa, FL. He received his Ph.D. in experimental condensed matter physics from the Indian Institute of Science. After postdoctoral research for several years, Hari joined USF in 2000 and established the Functional Materials Laboratory. His research spans a wide range of topics including magnetic nanoparticles, magnetic refrigerant materials, spin calorics and complex oxides. He has around 250 journal publications and given numerous invited talks. Hari is a Fellow of the American Physical Society and a Senior Member of IEEE. He is also an Associate Editor for Journal of Applied Physics. Hari has been closely involved with the MMM and INTERMAG conferences for more than 15 years serving as Publication Editor, Publication Chair and on program committees.

In living organisms, patterns and forms develop under a continuous flow-in and flow-out of matter and energy, without the need for external control. However, genetic factors alone cannot account for the full process i.e. they do not contain all the necessary information. Here’s where “generic”, physico-chemical principles come into play.

The once tantalizing goal of imitating this generic route in laboratory to develop the patterns, such as those decorating seashells or the fur of certain animals, has been achieved by coupling specific reaction pairs with pure diffusional transport in hydrogels.[1,2] These (often periodic) spatial concentration patterns can spontaneously emerge from an initially uniform concentration distribution, and can exist as long as the chemical environment is maintained stationary.

Such a chemical pre-patterning is only one possibility of morphogenesis. Biophysicists have pointed out that – most often – it is the interdependence between the biochemical and mechanical processes that effectively leads to the generation of chemical patterns and shapes. This synergistic approach, where the individual subsystems alone are not accountable for a specific behaviour, is experimentally modelled through the construction of soft, hydrogel-based actuators that operate with a self-regulated periodicity under appropriately fixed boundary conditions.[3,4]

[1] Horváth, Szalai, De Kepper, Designing Stationary Reaction-Diffusion Patterns in pH Self-Activated Systems ACCOUNTS OF CHEMICAL RESEARCH (2018) DOI: 10.1021/acs.accounts.8b00441
[2] Horváth, Szalai, De Kepper, An Experimental Design Method Leading to Chemical Turing Patterns SCIENCE (2009) DOI: 10.1126/science.1169973
[3] Horváth Chemomechanical oscillations with a non-redox non-oscillatory reaction CHEMICAL COMMUNICATIONS (2017) DOI: 10.1039/c7cc02497e
[4] Horváth Synergistic Chemomechanical Oscillators: Periodic Gel Actuators without Oscillatory Chemical Reaction MACROMOLECULAR SYMPOSIA (2015) DOI: 10.1002/masy.201500034

Dr. Judit Horváth received her Ph.D. in Colloid Chemistry at Eötvös Loránd University (ELTE) Budapest, where she became assistant professor and later research fellow. In between, she worked for five years in the “Nonlinear Structures and Dynamics” group at the Centre de Recherche Paul Pascal (CNRS) in Bordeaux. Since 2010, she has been supported by European and Hungarian research grants and fellowships. Her major research interest is to develop synergistic chemomechanical oscillators based on reaction–diffusion–mechanics coupling.

From March - May 2019, artist and architect Nasser Al-Salem from Saudi Arabia will be artist-in-residence at the Department of Materials/ETH, to exchange ideas, concepts and methods with researchers of the Department and to develop an artistic project.

This transdisciplinary collaboration is organized by the artists-in-labs program (AIL) of the Zurich University of the Arts (ZHdK) and part of the KAUST-Swiss Residency Exchange which was initiated in 2016. Through the exchange, Swiss artists can apply for a 3-months grant to work with researchers of the King Abdullah University of Science and Technology KAUST and Saudi artists to work with researchers from Swiss Universities.

Since 2003, the AIL has been facilitating artistic research by way of long-term residencies for artists in scientific laboratories and research institutes. The AIL promotes sustainable collaboration between artists and scientists of all disciplines, not just in Switzerland but all around the world. These long-term interdisciplinary and cross-border collaborations provide artists with an opportunity to critically engage with the sciences and their experimental and aesthetic dimensions. This includes explorations of the site of the laboratory, as well as a range of scientific topics, methods and technologies.

Our interests lie in the interaction and expansion of types of contemporary knowledge and artistic production, and the creative potential resulting from exploring the parallels and differences of scientific and artistic practices. We perceive our work as being culturally engaged and of a curatorial and mediatory nature.

Publications along with accompanying scientific research record the processes and results of these cross-border collaborations and offer reflections on them. In addition, in recent years the AIL has expanded to include a student-engaged dimension, seeing undergraduate arts and science students coming together to brainstorm some of the key issues of our times. The results include a range of science and arts projects, with outputs feeding into both scientific research and artistic practice.

All the collaborations the AIL produces are presented at various national and international exhibitions, symposia and workshops, making it possible to share findings and ideas, and to provide accessible discussions and aesthetic experiences to our students, peers and to the public.

http://www.artistsinlabs.ch
http://www.vimeo.com/artistsinlabs
http://www.facebook.com/artistsinlabs
http://www.instagram.com/artistsinlabs

1. F. G. Hamad, R. H. Colby and S. T. Milner, Macromolecules 48, 3725 and 7286 (2015).
2. F. G. Hamad, R. H. Colby and S. T. Milner, Macromolecules 49, 5561 (2016).
3. B. Nazari, H. Tran, B. Beauregard, M. Flynn-Hepford, D. Harrell, S. T. Milner and R. H. Colby, Macromolecules 51, 4750 (2018).
4. B. Nazari, A. M. Rhoades, R. P. Schaake and R. H. Colby, ACS Macro. Lett. 5, 849 (2016).
5. A. M. Rhoades, A. M. Gohn, J. Seo, R. Androsch and R. H. Colby, Macromolecules 51, 2785 (2018).
6. J. Seo, H. Takahashi, B. Nazari, A. M. Rhoades, R. P. Schaake and R. H. Colby, Macromolecules 51, 4269 (2018).

The IT Services have set up the ETH Research Data Hub (ETH RDH) platform, available to all ETH research groups working in quantitative research fields, to help them in the process of annotating, storing and managing all experimental and computational data.

This service provides an electronic lab book linked to the NAS storage server, which fulfils the ETH and SNF guidelines for logging and storing data. If it works well, it could be the solution to an outstanding problem.

It would be nice to have at least one representative of each group in DMATL taking part in this seminar.

https://www.ethz.ch/services/en/it-services/catalogue/software-business-applications/research-data-hub.html
https://labnotebook.ch

Coauthors
Georgios G. Vogiatzis, Lambert C.A. van Breemen.

Acknowledgement
Stimulating discussions with Doros Theodorou are gratefully acknowledged. This work is supported by the Dutch Polymer Institute (DPI), project no. 745ft14 and project EU-FP-001 COMPNANOCOMP, respectively.

References
[1] D.J. Wales, Energy landscapes, Cambridge University Press (2003).
[2] F.H. Stillinger and T.A. Weber, Hidden structure in liquids, Phys. Rev. A, 25, 978-989 (1982).
[3] G.G. Vogiatzis, L.C.A. van Breemen, and M. Hütter, Network topology of the states probed by a glassy specimen during physical aging, submitted to J. Chem. Theory Comput. (2018).

In the first part of the talk I will present a simulation model in which Brownian polymers are coupled to a discretized Navier-Stokes fluid, also called Smooth Particle Hydrodynamics. The coupling will conserve local momentum. The polymer model may be chosen to the taste of the user. In the case of massive flow through porous media, the polymer model necessarily must be very simple. I will present examples of simulations with single particle polymer models. Plenty of room will be left for critical questions.

In the second part I will present simulations of a steadily sheared soft matter model, probed by an orthogonal oscillatory shear flow with its gradient along that of the steady shear flow. Our main concern will be if Boltzmann’s superposition principle will hold in this situation. According to the latter, the shear relaxation modulus obtained with oscillatory experiments is equal to the stress relaxation modulus after a strain step. We will find that this principle does not hold in the present application, not even when the imposed steady shear has an infinitesimally small rate. Plenty of room will be left for critical remarks.

If time permits, I will present experiments on self-associating fluids, in which the relaxation of stresses after cessation of a sufficiently strong shear flow, is non-monotonic. I will argue that, contrary to the opinion of many of our colleagues, this behavior does not violate the laws of thermodynamics. Plenty of room will be left for critical remarks.

This talk is based on joint works with Assyr Abdulle (EPF Lausanne), Ibrahim Almuslimani (Univ. Geneva), Charles-Edouard Béhier (Univ. Lyon), Adrien Laurent (Univ. Geneva), Konstantinos C. Zygalakis (Univ. Edinburgh).

Having established this observation I argue that it may indeed be rational to increase one's degree of belief in the multiverse when confronted with fine-tuning for life - but not because the multiverse can explain why we exist despite the required fine-tuning.

Abstract:
Many biopolymers not only have advanced mechanical properties such as high modulus, toughness, and elasticity, but more importantly, exhibit dynamic characteristics including adaptive, malleable, and self-healing properties. Following inspirations from the Nature, Guan lab has developed several families of biomimetic soft materials imbued with various dynamic properties. In one system, we have designed a series of biomimetic modular polymers with folded nano-domains as the repeat units. These new material manifest an exciting combination of key mechanical, as well as adaptive, properties that have until now proven difficult to achieve in man-made systems. In another example, we have developed strong and autonomous self-healing polymers using various supramolecular and dynamic covalent interactions. In contrast to previous designs, our system spontaneously self-heals as a single-component solid at ambient conditions without the need of any external stimulus, healing agent, plasticizer, or solvent. Recently, we have also made significant progress in adaptive, malleable thermoset polymers via dynamic covalent bond exchange. The overarching concept for all these projects is to build a direct link between microscopic molecular properties and macroscopic bulk performance. In this seminar, I will discuss the design, synthesis, and property studies of these dynamic adaptive polymers.

Key References:
“Modular Design in Natural and Biomimetic Soft Materials” Angew. Chem. Int. Ed. 2011, 50, 9026.
“Multiphase Design of Stiff and Autonomic Self-Healing Polymers” Nature Chem. 2012, 4, 467.
“Direct correlation of single-molecule properties with bulk mechanical performance for the biomimetic design of polymers” Nature Materials 2014, 13, 1055.
“Self-Healing Multiphase Polymers via Dynamic Metal-Ligand Interactions” J. Am. Chem. Soc. 2014, 136, 16128.
“Malleable and Self-Healing Covalent Polymer Networks through Tunable Dynamic Boronic Ester Bonds” J. Am. Chem. Soc. 2015, 137, 6492.
“Large Continuous Mechanical Gradient Formation via Metal-Ligand Interactions” Angew. Chem. Int. Ed. 2017, 56, 15575.
“Silyl Ether as a Robust and Thermally Stable Dynamic Covalent Motif for Malleable Polymer Design” J. Am. Chem. Soc. 2017, 139, 14881.
“Recyclable, Strong, and Highly Malleable Thermosets Based on Boroxine Networks” J. Am. Chem. Soc. 2018, 140, 6217.

Short Biography:
Zhibin was raised in Anhui Province, China. He went to Beijing for receiving his high education. After finishing his undergraduate and master education at Peking University, he came to the United States for Ph.D. study. He received his Ph.D. degree in 1994 at the University of North Carolina, Chapel Hill. Following a postdoctoral stint at Caltech and a short career at DuPont, in 2000 he joined the faculty of the Department of Chemistry at UC Irvine as an assistant professor. He was promoted to Associate Professor with tenure in 2004, and to Full Professor in 2006. From 2006, he also became affiliated faculty of the Department of Biomedical Engineering and the Department of Chemical Engineering and Material Science at UC Irvine. He has received recognition of his research with several awards and fellowships, including the Japan Society for the Promotion of Science (JSPS) Fellowship, the Humboldt Bessel Research Award, the Camille Dreyfus Teacher-Scholar Award, the NSF CAREER Award, the Beckman Young Investigator Award, and an elected Fellow of the American Association for the Advancement of Science. He serves as the Chair for the 2018 Bioinspired Materials Gordon Research Conference in Les Diablerets, Switzerland.
Zhibin pursues a broad range of research interests that include new polymerization chemistry through catalysis, bioinspired materials design, self-healing and dynamic materials, single molecule force study of polymers, and functional biomaterials for gene delivery and immunology. His research work has been featured many times in scientific journals and popular newspapers such as C&EN News, Washington Post, Wall Street Journal, Los Angeles Times, CNN, Forbes, etc.

Let me know if you are interested in meeting Prof. Guan. There are still a few slots available.

I look forward to seeing many of you there!
Kind regards
Rafael

[1] C. C. Lin, E. Parrish, R.J. Composto; Macromolecules; 2016, 49, 5755.
[2] A. Karatrantos, N. Clarke, M. Kroger; Polymer Reviews, 2016, 56, 385.
[3] A. Karatrantos, N. Clarke, R.J. Composto, K. I. Winey; J. Chemical Physics, 2017, 146, 203331.
[4] R. S. Hoy, K. Foteinopoulou, and M. Kroger; Phys. Rev. E. 2009, 80, 031803.
[5] A.Karatrantos, Y. Koutsawa, P. Dubois, N. Clarke, and M. Kroger; İn preparation, 2018.
[6] M. Mu, N. Clarke, R.J. Composto, K.I. Winey; Macromolecules, 2009, 42, 7091.
[7] A. Karatrantos, R. J. Composto, K. I. Winey, M. Kroger, and N. Clarke. Macromolecules, 2012, 45, 7274.
[8] A. Karatrantos, N. Clarke, R.J. Composto, K. I. Winey; Soft Matter, 2013, 9, 3877.

Point defects can give rise to localized levels in a material forbidden gap; according to their position with respect to the conduction and valence bands, they can trap electrons or holes during irradiation with ionizing beams.

A significant influence of such trapping levels in luminescence processes is often observed. In general, carrier trapping at defects is a competitive process with respect to their prompt radiative or non radiative recombination. In scintillators, the presence of traps is harmful since they can give rise to slow tails in the scintillation time decay. Conversely, traps are profitably exploited in persistent phosphors and in dosimeters.

Thermally stimulated luminescence (TSL) studies are frequently employed for the investigation of point defects; wavelength resolved measurements, where the amplitude of the TSL emitted light is measured both as a function of temperature and emission wavelength, are particularly useful for a deep understanding of traps and recombination centres.

The seminar is devoted to a description of the investigation of point defects by wavelength resolved TSL with emphasis on the kind of information that can be found, like the energy position of the trapping levels, their thermal stability, and the kind of recombination mechanism. Experimental procedures and methods of data analysis are presented and compared, in order to give a picture of the potential of this high sensitivity technique. In addition, the capability to evidence less common features will also be highlighted, like the presence of local disorder, the existence of microscopic defect aggregates, and the occurrence of athermal or thermally assisted tunneling recombinations. Finally, it will be shown that the technique can also be exploited as a spectroscopic tool to investigate the position of activators energy levels.

The discussion is grounded on several examples concerning TSL studies in selected materials featuring different trapping-recombination mechanisms, including crystalline and amorphous systems as well as optical ceramics.

All interested students and colleagues are kindly invited to attend the seminar.

Capillary suspensions are three-phase fluids comprising a solid and two immiscible liquid phases. Addition of a small fraction of the secondary liquid phase to a suspension of particles dispersed in the so-called primary or bulk phase leads to the formation of a strong sample spanning particle network, even at low particle loadings. This particle network gains its strength from the capillary forces inferred from the added secondary liquid no matter whether it wets the particles better or worse than the primary liquid. This attractive force is typically orders of magnitude stronger than the ubiquitous van der Waals attraction. Accordingly, capillary suspensions exhibit a paste-like texture and a strongly shear thinning flow behavior. They are highly resistant to sedimentation and flow properties can be tuned in a wide range according to different processing or application demands. Various innovative products in very different fields of application have been introduced and capillary suspensions have been utilized as precursors for highly porous sintering materials to be used as light weight construction materials, membranes or catalysts. Capillary suspensions can be used in classical injection molding or extrusion processes but due to their unique flow properties they are especially suited for direct-ink-writing (DIW) type of 3D printing applications. The capillary suspension concept is especially useful for printed electronics since pastes can be designed without non-volatile organic components (e.g. surfactants, rheology control agents, binders) often deteriorating electrical properties. Conductive inks for front side metallization of solar cells and pastes for lithium-ion battery electrodes with high crack-resistance, unique shape accuracy and surface uniformity have been obtained. High purity silver and nickel layers with conductivity two times higher than obtained with state-of-the-art, commercial materials have been developed. The capillary suspension concept can be easily applied to various other systems using inorganic or even organic conductive particles and represents a fundamental paradigm change to the formulation of pastes for printed electronics.

Short CV:
Prof. Dr. Norbert Willenbacher (KIT) is head of the Institute of Mechanical Process Engineering and Mechanics at Karlsruhe Institute of Technology (KIT) since 2004. He received his diploma degree in Physics and his PhD from the University of Mainz. After his dissertation at the Max-Planck-Institute for Polymer Research he joined BASF SE as a research associate in the fields of rheology of complex fluids and adhesion of soft polymers for 15 years. Prof. Willenbacher is president of the German Society of Rheology, assigned member of the ProcessNet Technical Committee on Rheology, and member of the Editorial Board of Rheologica Acta.

Developing materials is essential to addressing the grand technological challenges of the XXIst century. Without new materials and processes, advances in areas that we take for granted, ranging from biomedicine to telecommunications, energy storage, and manufacturing of complex structures will either not happen or not be sustainable.

Materials Day is an opportunity to get to know the most advanced research directions in the Department of Materials at ETH Zürich in a one-day symposium, which includes talks, a prize award, and poster sessions, as well as opportunities for convivial discussions over lunch and coffee.

Join us for a day of exciting insights into Materials Science!

I will describe an algorithm that can effectively perform Brownian Dynamics of as many as one million colloidal particles confined to diffuse on a planar interface. The algorithm, which is a q2D version of the fluctuating Force Coupling Method (FCM), uses fluctuating hydrodynamics to incorporate Brownian motion and uses two-dimensional FFTs to achive a dramatic speedup over fully three-dimensional simulations. I will present results obtained using this algorithm on diffusive mixing of a binary mixture of particles in q2D, including enhanced collective diffusion, as well as results on giant nonequilibrium fluctuations in q2D. I will discuss the differences with truly two-dimensional systems, as well as particles confined near boundaries, and point to several interesting physical questions that arise from the unusual nature of diffusion in q2D.

References

As every year, the SMW (the materials student association) is organizing the “Bergfest”, a great barbeque event for meeting each other and sharing a drink. Find the details below:

Next Thursday, 11th May. It starts at 17:00 and will take place at the barbecue area above the ASVZ.

The Department of Materials and the SMW will provide side dishes and refreshments but you have to bring your own proteins.

Looking forward to seeing you there,
Ralph Spolenak

On the legal basis of the Association of the Cantonal Fire Insurers (VKF), the Executive Board of the Operations Department has placed an order to carry out periodic integral tests on the service installations system in the building. Such a test has already been successfully carried out in the HCI and HPI buildings on 7 January 2013. For this reason, a repetition is scheduled for 12 January 2017.

Goal: Ensure personal safety, property protection, and operational safety in the HCI building.

Two test scenarios will be carried out:

• 1. Total power outage followed by emergency power supply.
• 2. Fire drill in various parts of the building.

Affected buildings: HCI, HCP, HPI

Day: Thursday, 12. January 2017
Duration of tests: 07.00 - ca. 15.00
1. Complete power shutdown (60Min): 08.00 - ca. 09.00
2. Fire drills (per Finger): 09.00 - ca. 15.00

17:00 Uhr

Begrüssung
Prof. Manfred Fiebig, Vorsteher
Prof. Nicola Spaldin, Studiendirektorin

Next Exit Future - Wie verändert Innovation unsere Gesellschaft?
Dr. h. c. Ranga Yogeshwar, Wissenschaftsjournalist & Moderator

Rückblick der Studierenden
Absolventen der Materialwissenschaft

Überreichung der Diplome
Prof. Manfred Fiebig & Prof. Nicola Spaldin

Auszeichnungen und Preise
Prof. Nicola Spaldin
Dr. Sara Morgenthaler, Präsidentin der Alumni-Vereinigung

Schlussworte
Prof. Manfred Fiebig

17:00 Uhr

Moderation: Dr. Andrea Schrott, Studienkoordinatorin
Musik: Marco Santilli (Klarinette) & Ivan Tibolla (Akkordeon)

Microfluidics in combination with microbeam X-ray scattering is currently being developed into a powerful experimental methodology suitable for the time-resolved investigation of nanostructures, particle alignment and serial protein crystallography at synchrotrons and X-ray Free Electron Lasers (XFELs). This experimental approach enables the in situ study of kinetics with nano- or atomistic resolution by using X-ray compatible microflow chips and rapid mixing microfluidic liquid jet devices [1-6].

As an example, our microfluidic SAXS experiments at the microfocus beamline P03 (PETRA III, DESY) revealed the striking effect, that after passing a narrow section, polymer wormlike micelle and elongated particles are rotated perpendicular to the flow direction, keeping this orientation over the remaining length of the channel [1,2]. The flow-alignment of cylindrical, wormlike or fibrous structures is central to many processing steps such as in the production of nanocomposite materials, (micro-)fibers, during injection molding or the flow of cells and proteins through thin capillaries.

We also present lithography-based microfluidic devices that produce liquid jets with μm diameters (0.9 to 5 μm) at very low flow rates (150 to 1000 μl h-1) under atmospheric or vacuum conditions [5]. This microfluidic liquid jet system with highly reproducible geometries is based on the gas dynamic virtual nozzle (GDVN) design suitable for structural biology at serial femtosecond X-ray nanocrystallography [6] and time-resolved rapid mixing experiments [3,5].

References
[1] M. Trebbin, S. V. Roth, J. Thiele, S. Förster et al., Proc. Natl. Acad. Sci. USA 110, 6706–6711 (2013) doi:10.1073/pnas.1219340110.
[2] G. Benecke, M. Trebbin, S. V. Roth, P. Fratzl et al., J. Appl. Cryst. 47, 1797-1803 (2014) doi:10.1107/ S1600576714019773.
[3] S. With, M. Trebbin, S. V. Roth, S. Förster et al., Langmuir 30, 12494−12502 (2014) doi:10.1021/la502971m.
[4] S. M. Taheri, M. Trebbin, S. Förster et al., Soft Matter 8, 12124 (2012) doi:10.1039/C2SM26777B.
[5] M. Trebbin, H. N. Chapman, S. Förster et al., Lab Chip 14(10), 1733-45 (2014) doi:10.1039/C3LC51363G.
[6] H. N. Chapman et al., Nature 470, 73–77 (2011) doi:10.1038/nature09750.