Microsystems development and their fabrication are a highly attractive and challenging scientific domain bridging microelectronic, physics, chemistry, mechanics and material sciences. Recent progresses have allowed highly integrated and high-performance Micro or Nano Electro Mechanical Systems (classically denoted as MEMS or NEMS) to be built (see figure). One key point in the future development of such systems is the choice of tailored materials.
In that respect, metallic glasses provide a vast and untapped potential. Indeed, metallic glasses share with several other nanomaterials exceptional properties and in particular an elastic limit approaching the theoretical limit, large deformation ability and hence a very important elastic energy storage ability, a high hardness, a resistivity similar to their crystalline counterparts, a high endurance limit, a thermal expansion coefficient intermediate between ceramics and metals, interesting magnetic properties, etc. Their main drawbacks are their almost complete lack of homogeneous plastic deformation at room temperature and their relatively high fabrication costs. These limitations have hindered industrial application for bulk metallic glasses. However, recent researches have shown that those materials behave plastically when they are produced as thin films (smaller than few micrometers thick) while their fabrication cost is competitive.
The project aims to use these outstanding properties to improve efficiency of micro- and nano-systems. Two application domains will be investigated, one in the coating industry and the other in the domain of nanoelectronics. (1) Anti-scratch coatings on glasses will be studied taking advantage of the high hardness and ductility of thin film of metallic glasses. (2) Resonators for filtering applications in MHz range and parametric amplifiers based on MEMS capacitors for harsh environment operation will also be developed taking advantage of the high elastic limit of metallic glass thin layers.
The first steps of the work will concern the structure characterization of the metallic glass thin films and the extraction of advanced data of their mechanical properties. The metallic glass layer deposition conditions are already under investigation in Grenoble thanks to the Minatec facilities and the new on-chip nanomechanical testing concept developed at UCL will be used for on-chip mechanical testing. The metallic glass thin film development will be carried out in Grenoble while the MEMS fabrication and their analysis will be done in the UCL’s clean room facilities (WINFAB) that have expertise in this field.
This research will allow the PhD student to tackle an interdisciplinary project on an exciting subject at the frontier between materials science, physics and mechanics of materials. It requires good background in these fields and a strong motivation for experimental work in the field of nanotechnology.
ICTEAM & iMMC, Université catholique de Louvain (UCL), Belgium: mechanical characterization and modelling of thin films, micro and nanofabrication, clean room facilities (WINFAB). The new lab-on-chip methodology developed at UCL over the last 6 years will offer a versatile and unique tool to investigate the nanomechanics of metallic glass thin films.
SIMAP/GPM2 group, Grenoble INP: metallic glasses fabrication and mechanical behaviour. The group has worked for a long time on macroscopic mechanical characterisation and macroscopic fabrication of metallic glasses. Recently, they developed deposition expertise and handling of metallic glass thin films.
AGC Glass Europe, European R&D Centre (http://www.agc-glass.eu/)