Nano-tribology

 

Attached to the Nanosciences group since February, 2015, this team (2 assistant-professors) aims to study fundamental phenomena that control the friction and the wear in the microsystems, by using an original approach involving multi-asperities nanometric contacts rather than mono-asperities. In this context, the phenomena studied at nanometric scale can be transposed easier, by a multi-physics ascending approach at upper levels in order to control a MEMS macroscopic contact. This approach combines experimental tests under controlled environment with multi-scales numeric simulations (FEM, BEM and DEM). These simulations use particularly discrete elements method (DEM) unique in France, where mobile cellular automatons (MCA) allow to take account of formation and action of more or less reactive nanostructured tribofilms within the contact. The reactivity of this tribo-active interface can be controlled, experimentally and in real-time, by the application of external stimuli so that to influence the tribologic behaviour of the microsystem. As for the practical achievements, this theme leads to the creation of : (i) multi-architectural surfaces allowing the control of stick/slip phenomenon in micro-manipulation, (ii) adjustable self-lubricating coatings for luxury watch and (iii) surfaces with friction level that can be dynamically modified in the microsystems. As the nanoparticles, nanocomposites, tyre or watch industries are regularly faced to nanotribologic problems, applied research activities for these sectors have been achieved.