Subnanometer positioning and drift compensation with tunneling current

International audienceThis paper introduces the tunneling current as a sensor to detect and control displacements of Micro and Nano Electromechanical Systems (MNEMS). Due to its extremely small magnitude, the tunneling current can not be used without an appropriate control strategy. A control methodology involving two feedback loops is proposed to control displacements with an accuracy of 40pm while also compensating the sensor drift. With this strategy, controlling displacements with an amplitude larger than one nanometer is possible, extending the predicted capabilities of tunneling current by the literature. The overall approach is a solution for control of macro to nano systems and may be embedded in positioning applications requiring a very high degree of accuracy