Materials Science, Biomaterials, Surfaces, Coatings and Films, Polymers and Plastics
158
Scopus Publications
Scopus Publications
Thermophysical properties and solidification behavior of liquid Vit106a in microgravity Damien Terebenec, Markus Mohr, Rainer Wunderlich, Hans-Jörg Fecht, Stephan Schneider, Alex Dommann, Antonia Neels Npj Microgravity, 2026 Understanding thermophysical properties such as surface tension ( σ ), total hemispherical emissivity ( ε ), specific heat capacity ( c p ) and viscosity ( η ) as a function of temperature is essential for optimizing the vitrification of bulk metallic glasses (BMGs). In this study, the thermophysical properties of liquid Vit106a were measured aboard the International Space Station (ISS) using the electromagnetic levitator (EML). The surface tension σ exhibited a similar value with other Zr-based BMG, with a weak temperature dependence described by σ(T) = 1.557–4.36 ×10 −5 × (T - 1106) N.m −1 . The viscosity temperature-dependence η(T) was analyzed using the Vogel–Fulcher–Tammann (VFT) equation, yielding a kinetic fragility parameter of D* = 9.8 at high temperature, compared to D* = 21.6 at low temperature, that indicates a fragile-to-strong transition characteristic of Zr-based metallic glass formers. XRD analysis confirms full crystallization of the sample, despite being cooled at a rate of 16 K.s⁻¹, over nine times faster than the critical cooling rate of 1.75 K.s⁻¹ reported in the literature. The crystallized sample reveals a heterogeneous distribution of binary intermetallic phases, including ZrAl 3 , Zr 2 Cu, Zr 2 Ni, ZrAl and Nb 2 Ni. These findings provide insights into the thermophysical behavior of liquid Vit106a for large-scale manufacturing but also raise important questions regarding its good glass-forming ability for larger casting thickness.
Multi-scale and multi-energy non-destructive X-ray analysis of the European Retrievable Carrier (EURECA) Robert Zboray, Claudia Roeoesli, Alexander Flisch, Mathieu Plamondon, Rolf Kaufmann, Carina von Deschwanden, Kai Zweiacker, Thomas Lüthi, Tobias Bandi, Grégoire Bourban, Volker Gass, Damian Amstutz, Alex Dommann, Antonia Neels Acta Astronautica, 2025 The reduction in costs for space travel and scientific experiments in microgravity raises the question of equipment reusability. This goal can only be achieved if the space travel associated system degradations are fully understood. Non-destructive analysis of components post-flight can significantly reduce space travel expenses by identifying defects caused by the harsh conditions of launch and space environments and highlighting potential vulnerabilities. The concept of equipment reusability was first considered in 1992 with the first launch of the EURECA spacecraft, which was retrieved 11 months later. We present a multi-scale and multi-modal non-destructive analysis, using various X-ray systems, of the retrieved EURECA spacecraft to evaluate how launch, retrieval, and the harsh space environment impacted its support structure and payload. We discuss the unique challenges of X-ray imaging analysis due to the spacecraft's size and the multi-material composition of both the craft and its payload, and how these challenges were addressed. While early studies focused on surface defects, we provide an internal view of the EURECA satellite's support structure and experimental modules (payload) through a combination of X-ray methods. Our analysis spans more than three orders of magnitude for the object size, and five orders of magnitude with respect to resolution, capturing millimeter-scale details of the satellite and atomic-scale information about the material's crystal structure. Given the retrospective nature of this study, we hypothesize that the defects identified may be linked to differences in thermal expansion between materials, compounded by the extreme temperature gradients observed in space and during experiments conducted inside the modules.
Advancing Understanding of High-Temperature Micro-Electro-Mechanical System Failures with New Simulation-Assisted Approach Weronika Lidia Sadurska, Matthias Imboden, Jürgen Burger, Alex Jean Dommann Sensors, 2025 High-temperature micro-electro-mechanical systems (MEMSs) are critical for applications in extreme environments and applications where the operating temperature can exceed 1000 °C, but their long-term performance is limited by complex failure mechanisms, including material degradation caused by atomic migration. This study introduces a simulation-assisted approach to analyze and predict the dominant failure modes, focusing on vacancy fluxes and their driving forces, within high-temperature MEMS structures. The focus is on tungsten-based structures operating at a temperature of 1580 °C. This approach couples electric-, stress- and temperature-dependent simulations to evaluate atomic migration pathways, which are key contributors to failure. This study demonstrates that void accumulation, driven by vacancy migration, results in localized current density increase, hotspot formation, and accelerated structural degradation. The mean time to failure (MTTF) is shown to have exponential dependence on temperature and inverse-square dependence on current density, highlighting the critical role of these parameters in device reliability. These findings provide a deeper understanding of the failure mechanisms in high-temperature MEMSs and underscore the need for design strategies that mitigate electromigration and stress-induced void growth to enhance device performance and longevity.
Partial crystallization in Pd-BMG systems: From understanding structure towards influencing functionality through temperature-time series SabrinaL.J. Thomä, Robert Zboray, Anthony Chevalier, Ruggero Frison, Romuald Sauget, Silke Prades-Rödel, Roland Logé, Andreas Blatter, Alex Dommann, Antonia Neels Journal of Materials Research and Technology, 2024 Small quantities of crystalline domains created in an amorphous matrix are seen as an active driver for enhanced properties in bulk metallic glasses (BMGs). We investigated partial crystallization and phase transformations through a series of isotherms at 370°C performed on amorphous Pd-based BMG samples with the nominal composition of Pd 43 Cu 27 Ni 10 P 20 (Pd-BMG) and a density of 9.425 g/cm 3 . X-ray based methods such as X-ray diffraction (XRD) and phase enhanced micro-computed tomography (μ-CT) have been pushed to their limits for studying atomic structure and morphology, while time available before crystallization has additionally been investigated via differential scanning calorimetry (DSC), and are combined with optical microscopy (OM), scanning electron microscopy (SEM), and hardness measurements for their mechanical properties. We reveal that Pd-based BMG samples isothermally treated at 370 °C start to crystallize after 20 min and still undergo phase transformations and recrystallization even after being fully crystalline after 60 min of the isothermal treatment. Interestingly, 3D phase enhanced micro-computed tomography shows a clear separation of two domains of slightly different densities. We highlight X-ray tomographic scans, allowing the 3D spatial visualization of extremely low-density contrast in different material domains, thus providing a multi-scale physical description of the Pd-BMG system. Interesting is the fact, that the re-crystallization is not homogenous and the crystalline domains can reach large size of (100–200 μm) in an amorphous matrix. • Holistic X-ray based approach for understanding BMG composite structures towards functionality shaping. • First laboratory nano-CT investigation to quantify phase separation and crystallization in metallic glasses. • Investigating crystallization kinetics based on temperature-time series (isotherms). • Multiparametric materials characterization including elemental analysis and mechanical properties (hardness VH).
Exploring the thermally-controlled fentanyl transdermal therapy to provide constant drug delivery by physics-based digital twins Flora Bahrami, Agnes Psikuta, René Michel Rossi, Alex Dommann, Thijs Defraeye European Journal of Pharmaceutical Sciences, 2024 Transdermal drug delivery is suitable for low-molecular-weight drugs with specific lipophilicity, like fentanyl, which is widely used for cancer-induced pain management. However, fentanyl's transdermal therapy displays high intra-individual variability. Factors like skin characteristics at application sites and ambient temperature contribute to this variation. In this study, we developed a physics-based digital twin of the human body to cope with this variability and propose better adapted setups. This twin includes an in-silico skin model for drug penetration, a pharmacokinetic model, and a pharmacodynamic model. Based on the results of our simulations, applying the patch on the flank (side abdominal area) showed a 15.3 % higher maximum fentanyl concentration in the plasma than on the chest. Additionally, the time to reach this maximum concentration when delivered through the flank was 19.8 h, which was 10.3 h earlier than via the upper arm. Finally, this variation led to an 18 % lower minimum pain intensity for delivery via the flank than the chest. Moreover, the impact of seasonal changes on ambient temperature and skin temperature by considering the activity level was investigated. Based on our result, the fentanyl uptake flux by capillaries increased by up to 11.8 % from an inactive state in winter to an active state in summer. We also evaluated the effect of controlling fentanyl delivery by adjusting the temperature of the patch to alleviate the pain to reach a mild pain intensity (rated three on the VAS scale). By implementing this strategy, the average pain intensity decreased by 1.1 points, and the standard deviation for fentanyl concentration in plasma and average pain intensity reduced by 37.5 % and 33.3 %, respectively. Therefore, our digital twin demonstrated the efficacy of controlled drug release through temperature regulation, ensuring the therapy toward the intended target outcome and reducing therapy outcome variability. This holds promise as a potentially useful tool for physicians.
Electromagnetic levitation containerless processing of metallic materials in microgravity: thermophysical properties M. Mohr, Y. Dong, G. P. Bracker, R. W. Hyers, D. M. Matson, R. Zboray, R. Frison, A. Dommann, A. Neels, X. Xiao, J. Brillo, R. Busch, R. Novakovic, P. Srirangam, H.-J. Fecht Npj Microgravity, 2023 Transitions from the liquid to the solid state of matter are omnipresent. They form a crucial step in the industrial solidification of metallic alloy melts and are greatly influenced by the thermophysical properties of the melt. Knowledge of the thermophysical properties of liquid metallic alloys is necessary in order to gain a tight control over the solidification pathway, and over the obtained material structure of the solid. Measurements of thermophysical properties on ground are often difficult, or even impossible, since liquids are strongly influenced by earth’s gravity. Another problem is the reactivity of melts with container materials, especially at high temperature. Finally, deep undercooling, necessary to understand nucleus formation and equilibrium as well as non-equilibrium solidification, can only be achieved in a containerless environment. Containerless experiments in microgravity allow precise benchmark measurements of thermophysical properties. The electromagnetic levitator ISS-EML on the International Space Station (ISS) offers perfect conditions for such experiments. This way, data for process simulations is obtained, and a deeper understanding of nucleation, crystal growth, microstructural evolution, and other details of the transformation from liquid to solid can be gained. Here, we address the scientific questions in detail, show highlights of recent achievements, and give an outlook on future work.
Correlated disorder by defects clusters in LiNbO3 single crystals after crystal ion-slicing Simone Dolabella, Alexandre Reinhardt, Ausrine Bartasyte, Samuel Margueron, Amit Sharma, Xavier Maeder, Alex Dommann, Antonia Neels, Aurelio Borzì Materials and Design, 2023 LiNbO3 (LNO) is a material suitable for high-frequency and wideband RF filters as well as photonic applications due to its outstanding piezoelectric and optical properties. Applications such as thin-film bulk acoustic wave resonators or highly confined electro-optic modulators require thin films, which are still challenging to be obtained with the necessary crystalline quality by deposition methods. Alternatively to deposition, crystal ion-slicing (CIS) or Smart CutTM enables obtaining thin films hundreds of nanometers thick from the bulk single-crystal utilizing high-energy and dose implantation of light atoms. The price to pay is the partial degradation of the initial crystalline perfection, which translates to a degradation of the piezoelectric performance of the material if the CIS-induced damage is not eliminated. This work aims to understand the physics of the recrystallization process of the CIS-damaged LNO crystal upon thermal annealing. The study of the coherent and diffuse scattering by high-resolution X-ray diffraction, complemented by micro-Raman backscattering spectroscopy and Transmission Electron Microscopy (TEM), allowed to study the recovery of the crystallinity from the CIS-induced lattice strain and stress and the progressive reduction of the defects clusters dimension.
HRXRD and micro-CT multiscale investigation of stress and defects induced by a novel packaging design for MEMS sensors Aurelio Borzì, Robert Zboray, Simone Dolabella, Sébastien Brun, Florian Telmont, Peter Kupferschmied, Jean-François Le Néal, Pedrag Drljaca, Gianni Fiorucci, Alex Dommann, Antonia Neels Applied Materials Today, 2022 Advanced methods such as high-resolution X-ray diffraction and X-ray micro CT allow highly precise determination of materials' residual stress, volume, and lattice defects. Their conjoint exploitation offers a powering tool to facilitate the industrial implementation of novelties in microfabrication. The wafer-level packaging represents a critical step of the MEMS microfabrication resulting in a hermetic, defect- and stress-free interface. For the first time, such critical parameters are investigated related to a novel wafer-bonding process, namely Impulse Current Bonding (ICB), and compared to the standard anodic bonding technology used for MEMS production. The ICB does not induce any relevant residual stress at the interface above the limit of 1 MPa, determined by the unrivaled strain detectability of HRXRD. The bonding interface is devoid of any defects, as defined by X-ray micro-CT studies. The ICB technology reduces the thermal budget of the packaging up to 85% compared to the anodic bonding, which outlines an outstanding step forward in reducing the energy footprint. The extension of ICB to other materials systems such as glass to ceramic or metals makes this technology a promising candidate for numerous applications, including the design of biocompatible devices for bio-implants.
Lattice Strain and Defects Analysis in Nanostructured Semiconductor Materials and Devices by High-Resolution X-Ray Diffraction: Theoretical and Practical Aspects Simone Dolabella, Aurelio Borzì, Alex Dommann, Antonia Neels Small Methods, 2022 The reliability of semiconductor materials with electrical and optical properties are connected to their structures. The elastic strain field and tilt analysis of the crystal lattice, detectable by the variation in position and shape of the diffraction peaks, is used to quantify defects and investigate their mobility. The exploitation of high‐resolution X‐ray diffraction‐based methods for the evaluation of structural defects in semiconductor materials and devices is reviewed. An efficient and non‐destructive characterization is possible for structural parameters such as, lattice strain and tilt, layer composition and thickness, lattice mismatch, and dislocation density. The description of specific experimental diffraction geometries and scanning methods is provided. Today's X‐ray diffraction based methods are evaluated and compared, also with respect to their applicability limits. The goal is to understand the close relationship between lattice strain and structural defects. For different material systems, the appropriate analytical methods are highlighted.
Thermophysical Properties of Bulk Metallic Glasses Markus Mohr, Yue Dong, Douglas C. Hofmann, Antonia Neels, Alex Dommann, William L. Johnson, Hans-Jörg Fecht Minerals Metals and Materials Series, 2022
Elastic and Plastic Stress Relaxation in Highly Mismatched SiGe/Si Crystals Fabio Isa, Arik Jung, Marco Salvalaglio, Yadira Arroyo Rojas Dasilva, Mojmír Meduna, Michael Barget, Thomas Kreiliger, Giovanni Isella, Rolf Erni, Fabio Pezzoli, Emiliano Bonera, Philippe Niedermann, Kai Zweiacker, Antonia Neels, Alex Dommann, Pierangelo Gröning, Francesco Montalenti, Hans von Känel MRS Advances, 2016
3D heteroepitaxy of mismatched semiconductors on silicon Claudiu V. Falub, Thomas Kreiliger, Fabio Isa, Alfonso G. Taboada, Mojmír Meduňa, Fabio Pezzoli, Roberto Bergamaschini, Anna Marzegalli, Elisabeth Müller, Daniel Chrastina, Giovanni Isella, Antonia Neels, Philippe Niedermann, Alex Dommann, Leo Miglio, Hans von Känel Thin Solid Films, 2014
Strain relaxation of GaAs/Ge crystals on patterned Si substrates A. G. Taboada, T. Kreiliger, C. V. Falub, F. Isa, M. Salvalaglio, L. Wewior, D. Fuster, M. Richter, E. Uccelli, P. Niedermann, A. Neels, F. Mancarella, B. Alén, L. Miglio, A. Dommann, G. Isella, H. von Känel Applied Physics Letters, 2014
Epitaxial Ge-crystal arrays for X-ray detection T Kreiliger, C V Falub, F Isa, G Isella, D Chrastina, R Bergamaschini, A Marzegalli, R Kaufmann, P Niedermann, A Neels, E Müller, M Meduňa, A Dommann, L Miglio, H von Känel Journal of Instrumentation, 2014
Three-dimensional epitaxial Si1-xGex, Ge and SiC crystals on deeply patterned Si substrates Hans von Känel, Fabio Isa, Claudiu V. Falub, Eszter Judit Barthazy, Elisabeth Müller Gubler, Daniel Chrastina, Giovanni Isella, Thomas Kreiliger, Alfonso Gonzalez Taboada, Mojmir Meduna, Rolf Kaufmann, Antonia Neels, Alex Dommann, Philippe Niedermann, Fulvio Mancarella, Marco Mauceri, Marco Puglisi, Danilo Crippa, Francesco La Via, Ruggero Anzalone, Nicolo Piluso, Roberto Bergamaschini, Anna Marzegalli, Leo Miglio Ecs Transactions, 2014
Integration of GaAs on Ge/Si towers by MOVPE A. G. Taboada, T. Kreiliger, C. V. Falub, M. Richter, F. Isa, E. Müller, E. Uccelli, P. Niedermann, A. Neels, G. Isella, J. Fompeyrine, A. Dommann, H. von Känel Materials Research Society Symposium Proceedings, 2013
Analysis of stress in silicon-based microsystems by X-ray diffraction techniques Empc 2013 European Microelectronics Packaging Conference the Winding Roads of Electronics Packaging, 2013
Perfect crystals grown from imperfect interfaces Claudiu V. Falub, Mojmír Meduňa, Daniel Chrastina, Fabio Isa, Anna Marzegalli, Thomas Kreiliger, Alfonso G. Taboada, Giovanni Isella, Leo Miglio, Alex Dommann, Hans von Känel Scientific Reports, 2013
Space-filling arrays of three-dimensional epitaxial Ge and Si 1-xGe x crystals C. V. Falub, F. Isa, T. Kreiliger, R. Bergamaschini, A. Marzegalli, A. G. Taboada, D. Chrastina, G. Isella, E. Muller, P. Niedermann, A. Dommann, A. Neels, A. Pezous, M. Meduna, L. Miglio, H. von Kanel 2012 International Silicon Germanium Technology and Device Meeting Istdm 2012 Proceedings, 2012
Aging analysis for MEMS devices using X-ray techniques Ssi 2012 Smart Systems Integration Conference 2012, 2012
Towards miniature carbon-nanotube based X-ray sources Ssi 2012 Smart Systems Integration Conference 2012, 2012
Reliable hermetic MEMS chip-scale packaging Empc 2011 18th European Microelectronics and Packaging Conference Proceedings, 2011
Advanced in- and out-off plane high resolution X-ray strain analysis on MEMS Nanotechnology 2010 Electronics Devices Fabrication MEMS Fluidics and Computational Technical Proceedings of the 2010 Nsti Nanotechnology Conference and Expo Nsti Nanotech 2010, 2010
In-situ MEMS testing Nanotechnology 2010 Electronics Devices Fabrication MEMS Fluidics and Computational Technical Proceedings of the 2010 Nsti Nanotechnology Conference and Expo Nsti Nanotech 2010, 2010
Solid on liquid deposition J. Charmet, O. Banakh, E. Laux, B. Graf, F. Dias, A. Dunand, H. Keppner, G. Gorodyska, M. Textor, W. Noell, N.F. de Rooij, A. Neels, M. Dadras, A. Dommann, H. Knapp, Ch. Borter, M. Benkhaira Thin Solid Films, 2010
Silicon flexure-based micro-balance for batch weighing processes Proceedings of the 9th International Conference of the European Society for Precision Engineering and Nanotechnology Euspen 2009, 2009
Clinical applications of glass-ceramics in dentistry Wolfram Höland, Volker Rheinberger, Elke Apel, Christian van ’t Hoen, Marlies Höland, Alex Dommann, Marcel Obrecht, Corinna Mauth, Ursula Graf-Hausner Journal of Materials Science Materials in Medicine, 2006
Dual-axis single-mirror mechanism for beam steering and stabilisation in optical inter satellite links European Space Agency Special Publication ESA SP, 2003
Reciprocating silicon microtribometer Philippe Dubois, Stephane von Gunten, August Enzler, Urs Lippuner, Alex Dommann, Nicolaas-F. de Rooij Proceedings of SPIE the International Society for Optical Engineering, 2003
Low energy plasma enhanced chemical vapour deposition - Plasma enhanced deposition of epitaxial Si and SiGe Materials Research Society Symposium Proceedings, 2002
Structural and electrical characterization of Si-modfet structures grown at high rates by LEPECVD Materials Research Society Symposium Proceedings, 2000
Structural and electrical characterization of Si-MODFET structures grown at high rates by LEPECVD Materials Research Society Symposium Proceedings, 2000
