Robotic in situ stiffness cartography of InP membranes by dynamic force sensing

Typical methods of measuring mechanical properties at the micro-scale are destructive, and do not allow proper characterisation on resonant MEMS/NEMS. In this paper, a cartography of local stiffness variations on a suspended micromembrane is established for the first time, by a tuning-fork-based dynamic force sensor inside a SEM. Experiments are conducted on InP membranes 200nm thin, using a 9-DoF nano-manipulation system, complemented with virtual reality and automation tools. Results provide stiffness values ranging from 0.6 to 3 N/m on a single sample.