A system level modeling method for a MEMS variable cross-section beam driven by electrostatic force

A thin variable cross section beam is usually clamped at both ends. An electrostatic voltage applied to the electrode pad directly underneath the beam leads to a two-dimensional 2-D effect. The electrostatic energy stored in the capacitive beam-pad dielectric gap is decoupled from the mechanical deformation of the beam. A novel method was put forward here in order to describe this 2-D effect. Three improvements are taken into account. The simulations by a finite element method (FEM) CoventorWare have been compared with the novel model, and the error has been limited within 12%. It is shown that the 2-D model for the variable cross-section beam would be useful.