SIMULATION METHODS FOR MICROELECTROMECHANICAL STRUCTURES (MEMS) WITH APPLICATION TO A MICROTWEEZER

In this paper, we consider the simulation of microelectromechanical st ructures (MEMS). The objective of this work is to develop reliable num erical procedures that will help improve our understanding of MEMS beh aviors, and enable optimal design of MEMS. A hybrid FEM-BEM method is developed to solve the coupled electrostatics and mechanics equations. Sensitivity analysis is carried out using the direct differentiation approach (DDA) to compute the design sensitivity coefficients (DSCs). The DSCs can then be used to drive optimization procedures. The numeri cal approaches are validated on a simple MEMS device-the tungsten micr otweezer. The nonlinearity of the electrostatic force is found to domi nate the behavior of this device. Sensitivity analysis and optimizatio n procedures are used to compute critical parameters related to the no nlinear behaviors, as well as to solve inverse problems. The nonlinear behaviors of the tweezer are explained using a simple physical analog which is found to exhibit many of the same behaviors. Quantitative co mparisons of the simulated results with experiments are also presented .