The ROSETTA/MIDAS space mission intends to analyze the dust resulting from the Wirtanen comet using an Atomic Force Microscope (AFM). To scan the dust, an extremely fine mechanism able to produce displacement’s accuracy in the sub-micrometer range with a limited mass, is required. The only technology which can meet this specification is the piezoelectric
actuator associated to capacitive displacement sensors, which displays several advantages : solid state design, which means no friction, noise limited by the driving electronic, …