Dynamic pull-in and snap-through behavior in micro/nano mechanical memories considering squeeze film damping

Abstract

In this paper, a model for considering the effect of squeeze film damping in electrostatically-actuated micro/nano curved-beams is developed. Micro/nano curved-beams have a wide range of applications including micro/nano mechanical memories and RF resonators. In our model, effects of ambient pressure, air gap and different physical parameters on pull-in voltages and snap-through voltages are considered. Pull-in instability and snap-through buckling, the two most important phenomena in bistable MEMS/NEMS, are investigated extensively. Here, squeeze film damping is modeled by nonlinear Reynolds equation, and the curved beam is modeled by nonlinear curved form of Euler---Bernoulli (E---B) beam equation. Afterward, the dynamic response of the system is investigated by finite element method (FEM). Finally, the results are compared with two dimensional equivalent form of E---B beam, and classical plate theory (CPT). The results are very beneficial in bistable MEMS/NEMS design.