State of the art in prediction of mechanical behaviour of microsystems [MEMS]

Behavioural models as analytical expressions relating loading parameters, material properties, and geometry of the microstructure with its performance characteristics are essential items in the toolbox of the MEMS designer. Unfortunately, well-known classic equations, derived for idealized macrostructures, do not always work for microcomponents. This paper presents an overview of different approaches to predicting the mechanical behaviour of microsystems and problems that need to be addressed. Analytical and numerical techniques are mainly considered. The paper concentrates on the merits, utilities and wide applicability of numerical modelling of MEMS behaviour. The development of analytical expressions for predicting mechanical performance of microcantilever beams is demonstrated as a case study in this paper. Mathematical models of deflections of microcantilevers on supports (pillars or anchors) subjected to either uniform or concentrated external load were extracted from finite element simulation results and are presented in the paper. The models accurately predicts the deflections of the considered microstructures.