Dynamic and Static Pull-in instability of electrostatically actuated nano/micro membranes under the effects of Casimir force and squeezed film damping

In the current study, the effects of Casimir force and squeeze film damping on pull-in instability and dynamic behavior of electrostatically actuated nano and micro electromechanical systems are investigated separately. Linear elastic membrane theory is used to model the static and dynamic behavior of the system for strip, annular and disk geometries. Squeeze film damping is modeled using nonlinear Reynolds equation. Both equation of motion and nonlinear Reynolds equation are first nondimensionalized, and then discretized and solved by means of finite element method. Static pull-in analysis is performed and validated by previous researches, and then dynamic pull-in values are investigated and compared with static pull-in parameters. In the next step, the effect of squeeze film damping, ambient pressure and Casimir force on the system dynamics is studied. Results show significant effect of Casimir force and squeeze film damping on the system behavior which is considerable for fabrication and design.