Abstract

Micro-electro-mechanical-systems (MEMS) integrate, by definition, both electrical and mechanical components onto a microscale silicon substrate. Hence, in this regard it is often difficult to differentiate between mechanical and electrical influences on the microsystem. The inclusion of thermal gradients, as can be expected in harsh environments, for example, further tempers an already diluted microsystem response. Hence, the various combined input parameters need to be discretized, analyzed, and finally synthesized in order to obtain a systematic evaluation of microsystem performance. The main influences investigated here that will affect the elastic properties of MEMS cantilevers are microfabrication tolerances at the support boundary, applied electrostatic potentials used to deflect the microcantilever, thermal loads that mimic harsh environments and alter the physical dimensions of the microcantilever, structural geometry used to optimize and tune, for example, the dynamic response, and cutouts along the microcantilever used for mass reduction and also for tuning capabilities. Artificial springs are used to model boundary support conditions and electrostatic influences. These influences are investigated first separately and then in a synthesized manner in which they are all combined. The theoretical model is based upon the Rayleigh-Ritz energy method. This method is suitable for MEMS cantilevers under various applied influences, however, it is limited to microcantilevers without cutouts due to discontinuities created along the length of the cantilever by the cutouts. Hence, a segment Rayleigh-Ritz energy model was developed, in order to improve the theoretical formulation, based on a segmental approach in which the microcantilever is divided into segments that are a function of the number of cutouts