Some Design Considerations on the Electrostatically Actuated Fixed-Fixed End Type MEMS Switches

The nonlinear electrostatic pull-in behaviour of MEMS Switches in micro-electromechanical systems (MEMS) is investigated in this article. We used the distributed model when the electrostatic pressure didn't apply at the whole of the beam and applied only in the mid-part of the beam. In this part the electrostatic area is different from two other parts. The model uses Euler-Bernoulli beam theory for fixed-fixed end type beams. The finite difference method was used to solve the nonlinear equation. The proposed model includes the fringing effects of the electrical field, residual stress and varying electrostatic area effects. The numerical results reveal that the profile deflection of the MEMS Switch may not only influence the distribution of the electrostatic force but also considerably change the nonlinear pull-in voltage.