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

In this paper, we consider the simulation of microelectromechanical structures (MEMS). The objective of this work is to develop reliable numerical procedures that will help improve our understanding of MEMS behaviors, 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 numerical approaches are validated on a simple MEMS device-the tungsten microtweezer. The nonlinearity of the electrostatic force is found to dominate the behavior of this device. Sensitivity analysis and optimization procedures are used to compute critical parameters related to the nonlinear 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 comparisons of the simulated results with experiments are also presented.