A position feedback solution based on the acoustic signal produced by electrostatically driven MEMS scanning mirror

An acoustic signal is usually produced when the MEMS scanning mirror is working. In this paper, the acoustic signal is proposed to be used as the feedback signal of MEMS scanning mirror and an analytical model of the audio feedback is reported for the first time. The air behavior in MEMS scanning mirror is analyzed and Navier-Stokes equations in this situation is solved to derive the expression of the sound. It can be readily found that the parameter of the sound is related to the movement of the MEMS mirror. Resultingly, the information of the sound can be used as the position feedback signal of mirror. An experiment had been implemented to verify the model coming up with in this paper, which indicated the sound is an efficient feedback solution of the scanning mirror.