A Perturbation Method for the 3D Finite Element Modeling of Electrostatically Driven MEMS

Abstract

In this paper, a finite element (FE) procedure for modeling electrostatically actu-ated MEMS is presented. It concerns a perturbation method for computing electrostatic fielddistortions due to moving conductors. The computation is split in two steps. First, an un-perturbed problem (in the absence of certain conductors) is solved with the conventional FEmethod in the complete domain. Second, a perturbation problem is solved in a reduced re-gion with an additional conductor using the solution of the unperturbed problem as a source.When the perturbing region is close to the original source field, an iterative computation maybe required. The developed procedure offers the advantage of solving sub-problems in re-duced domains and consequently of benefiting from different problem-adapted meshes. Thisapproach allows for computational efficiency by decreasing the size of the problem.

Keywords

• Electrostatic field distortions
• finite element method
• perturbation method
• MEMS.