PhD students
Graduated as a mechatronic engineer from ENSA (Morocco), Sahar Jaddi obtained then an advanced master degree in nanotechnologies from UCL in 2017. Now, she is working on a PhD thesissince September 2017 under the supervision of Prof. Thomas Pardoen (iMMC) and Prof. Jean-Pierre Raskin (ICTEAM).
Her research deals with the development of a new testing method based on an-on-chip concept to measure the fracture toughness of freestanding submicron films. This device consists of two major components, a notched specimen and two actuators. When the test structure is released by etching the sacrificial layer, the two actuators contract, this in turn loads the specimen in traction. In order to define the stress intensity factor expression, which is given by this new model, analytical analysis and finite element simulations must be performed in addition to the experimental part, which is based on the microfabrication techniques. The second aspect of the thesis is to address fracture mechanisms in very thin film materials: silicon nitride, silicon oxide and metallic glass thin films have been selected. Ultimately, 2D materials like graphene will be investigated.
Romain Tuyaerts
Romain Tuyaerts graduated as a physical engineer from UCL in 2013. He is studying the electromechanical and optical behaviour of ZnO and AZO thin films, and the effect of internal stress on these properties. The films are deposited by reactive magnetron sputtering which allows to tune the properties and the internal stress on a wide range. The internal stress is measured in-situ during deposition with a multi-beam optical stress sensor (MOSS). After deposition, additional stress is applied with the lab-on-chip technique to determine Young's modulus and fracture strain. A modified version of the concept is used to measure resistivity, and charge carrier density and mobility, as a function of the strain.
Senior scientists, Postdoctoral researchers
Marie-Stéphane Colla, Dr, Senior scientist - Thin film mechanics
Marie-Stéphane Colla graduated in chemical and materials science engineering at the Université catholique de Louvain in 2009 (Belgium). Then, under the supervision of Prof. Thomas Pardoen (iMMC) and Prof. Jean-Pierre Raskin (ICTEAM), she accomplished a PhD on the study of the mechanical properties of thin films, more specifically on the plasticity and creep of freestanding nanocrystalline Pd films. The lab-on-chip technique developed previously at the UCL was adapted to deform Pd thin films. After the PhD, she worked for more than two years at the CRM Group in Liège on the development of industrially viable thin film solar cells on steel. Since June 2016, she is back at the UCL as a research engineer involved in various projects dealing with coatings and metallurgy.
Michaël Coulombier, Dr, Senior scientist - Thin film mechanics and lab on chip testing
Michaël Coulombier graduated as a material science engineer from UCL in 2006. He finished his PhD in 2012 under the supervision of Prof. Thomas Pardoen (iMMC) and Prof. Jean-Pierre Raskin (ICTEAM) developing a lab on-chip technique for nano-mechanical characterisation of thin films. Since then he has been a research assistant in iMMC involved in various projects dealing with material science, nanomechanical testing and tribology.
Audrey Favache, Dr, Senior scientist - Tribology: nanoindentation, nanoscratch and thin film mechanics
Audrey Favache obtained a PhD degree in the domain of process control in 2009 at Université catholique de Louvain (Belgium), after having graduated there as chemical engineer in 2005. Since then, she is working as a "senior" researcher on several applied research projects in collaboration with the industry in the domain of mechanics of materials. More particularly, she is interested in the link between the mechanical properties of the individual components of a complex system and the global mechanical response of this system. She applied this approach to the framework of tribology and contact mechanics for understanding the scratch resistance of coatings and multilayered systems. Her work covers both experimental aspects and finite element simulations. She is one of the reference persons at UCL concerning nanoindentation and nanoscratch measurements of thin films.
Sophie Ryelandt, Senior scientist
Sophie Ryelandt graduated as a physical engineer at Université catholique de Louvain in 1991. After having worked for six years at the R&D center of the Spadel company, she came back at UCL as a senior scientist. She is involved in various applied research projects in collaboration with the industry. Her research domains are dealing with material science, metallic composites, multilayered materials and coatings, additive manufacturing of metals, nanomechanical and mechanical testing and the link between microstructure and mechanical properties.
Alumni
Rémi Daudin, Dr, Postdoctoral researcher - Metallic glass thin films
Rémi Daudin graduated as a mechanical engineer at Université Grenoble Alpes (France) in 2008. He then performed is PhD work at the CEA Grenoble (2008-2012) where his research concerned the supercooling behavior of gold nano-droplets in interaction with Si substrates by in situ synchrotron surface diffraction. After a one year around the world bicycle trip, he worked as a post doc at the SIMaP laboratory in Grenoble (France) for three years (2013-2016) where he focused on mechanical and microstructural characterization of metallic nano-composites using in situ synchrotron tomography. He then joined the UCL-IMAP laboratory thanks to the Move-in-Louvain program (post-doc, 2016-2018). His scientific activities concern the investigation of the size and of the composition effects on the mechanical properties of metallic glasses thin films. His main interest is to probe, using nano-beam synchrotron X-ray diffraction, the distribution of the local strain inside the thin metallic glass films and correlate it to the macroscopic strain in order to reveal the internal micro-mechanisms governing the mechanical properties.
Mohamed Hammad - Nanomechanics of graphene
Mohamed Hammad (PhD student) is working on the characterization of mechanical properties of graphene. First part of his work is to characterize the properties of graphene/substrate system through nanoindentation and tribology measurements. The effects of graphene on the system response to elastic and plastic loading is explored and studied. Second part of the work is to build on-chip tensile testing devices based on the concept developed at UCL and to integrate graphene in this process as the test material. This device would be helpful to study properties of graphene under extreme uniaxial strains, as well as characterize the stress-strain response of graphene in uniaxial tensile tests. Several processing and characterization issues are studied.
Guerric Lemoine (also Division MEMA)
Guerric Lemoine graduated as materials engineer at Université catholique de Louvain in 2009. Combining both experiments and simulations, his doctoral research focus on the viscoplasticity and the strain localization in metallic thin films. The Lab-on-chip technique is used to characterize the yield stress, the ductility, the hardening behavior and the strain rate sensitivity of Ni thin films. Guerric is also working on the development of a localized necking model dedicated to thin films and nanocrystalline metals which aims at accounting for strain gradient plasticity effects, for grain size dependent strength, rate sensitivity and the possible contribution of creep/relaxation mechanisms. A dislocation-based crystal plasticity model has also been developed in order to study the mechanical and creep/relaxation behavior of the polycrystalline Pd thin films with high initial defect concentration, obtained by M-S Colla during her PhD thesis.