Fast analysis of MEMS micromirror based on multi-physical electro-mechanical-damping coupling method

Abstract This paper presents an algorithm to improve the computational efficiency of electrostatically driven scanning micromirror with staggered vertical combs. Firstly, a single vertical comb is treated with an approximate periodic boundary. Through mechanical analysis, the mapping relationship between the deflection angle of the comb and the torque is obtained. It is found that when the deflection angle is small, the torque acting on the comb changes little and can be considered as a constant value. Based on the mapping relationship, the electrostatic torque of a single axis electrostatic scanning mirror with different voltages is extracted by considering only the electrostatic field action. In the subsequent deflection analysis of the micromirror, the extracted torque is added to the mechanical field, and the electrostatic field can be ignored. In order to further simplify the model and improve the computational efficiency, an equivalent model was established on the basis of the original single-axis scanning mirror. Immediately after, considering the effect of air damping, solid mechanics and thermal-viscous acoustic coupling calculations of the single-axis electrostatic driven mirror are carried out. Finally, the maximum mechanical deflection angle of the micromirror under different atmospheric pressure is obtained. The model proposed in this paper transforms the electro-mechanical coupling calculation into separate calculation of electrostatic field and mechanical field, which greatly improves the calculation efficiency.