A Computationally Efficient Model of MEMS Stopper for Reliability Optimization

Abstract

MEMS stoppers are commonly used structures to prevent failures caused by mechanical overload such as shock and pressure. However, the numerical research of the stoppers could be computationally costly and non-convergent, since it involves non-linear mechanical features such as contact and collision. This poses difficulties to the reliability design and optimization of MEMS. This paper proposes a parametric model of MEMS stoppers that is computationally efficient for reliability design. The model converts the material and geometric characteristics of the stopper into a nonlinear spring system. The efficiency and convergence of numerical computation of the MEMS structure with stoppers were effectively improved through both static and transient FEM research examples. The stress distribution and transient displacement response obtained by this model were in good agreement with the calculation results of traditional contact algorithm in FEM examples. The overload-resistance of MEMS stoppers were further analyzed. Finally, we optimized the design of MEMS stopper's shape and stiffness based on the parametric model. The model proposed in this study is suitable for the design and optimization of the anti-overload structure of MEMS.