Nanorheology

From 1995 to 2005, I mainly developed scientific equipment for studying the rheology of liquids confined to the nanometric scale. The principle is that of a surface force machine: 2 macroscopic surfaces are approximated at a distance of a few nanometres, and the liquid film is made to flow by distance modulations of the order of 10 to 100 pm. The nano-rheometer was built in collaboration with Elisabeth Charlaix (ENS Lyon, then University of Lyon 1). It was built from scratch and typically represented 2/3 of my research activity. It is a thankless piece of instrumental work, the great difficulty of which is due to the combination of metrological problems (sensors, measurements, stability, noise density, etc.), mechanical problems (linearity, hysteresis, dissipation, resonance, etc.) and environmental problems (vibrations, pollution, drift, etc.). I was a very active contributor to this project: I developed the sensors (optical interferometry, capacitive), the mechanical characterisation of the elements (mechanical transfer functions, vibration modes, dissipation), a large part of the drift compensation, interfacing,