The tunnel current as a subnanometer motion sensor

This paper proposes a new approach in order to use the tunnel current as a position sensor at nanoscale. It is shown that electron tunneling commonly used in Scanning Tunneling Microscopes (STM) can be used to control the motion of a Nano Electromechanical System (NEMS) with an accuracy of 1.10^-12m/√Hz, at ambient temperature, and using only one electrostatic actuator. The designed control strategy is based on two feedback loops, robust control design, linearizing feedback, and a Kalman filter in order to minimize noises present at nanoscale.