The Normal Condition of Squeeze-film Damping Model for Torsion Micro-Resonators

The prediction of squeeze-film damping plays a significant role in the design of high Q MEMS devices. This paper presents an analytical solution for the effect of squeeze film damping on a rectangular torsion micro-mirrors whose torsion axis exists in different positions. We defined a variable l to represent the distance which torsion axis departs from its central axis. The double sine solution is derived from the linearized Reynolds equation to obtain the pressure distribution under the vibrating plate, and then calculate the analytical expression of the damping constant. Comparing the results with the finite element method(FEM), the accuracy of the model can be verified.