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Abstract: Because of the strong coupling between mechanical and electrical phenomena existing in electromechanical microdevices, some of them experience, above a given driving voltage, an unstable behavior called pull-in effect. The present paper investigates the application of topology optimization to electromechanical microdevices for the purpose of delaying this unstable behavior by maximizing their pull-in voltage. Within the framework of this preliminary study, the pull-in voltage maximization procedure is developed on the basis of electromechanical microbeams reinforcement topology design problem. The proposed sensitivity analysis requires only the knowledge of the microdevice pull-in state and of the first eigenmode of the tangent stiffness matrix. As the pull-in point research is a highly non-linear problem, the analysis is based on a monolithic finite element formulation combined with a normal flow algorithm (homotopy method). An application of the developed method is proposed and the result is compared to the one obtained using a linear compliance optimization. Moreover, as the results provided by the developed method do not comply with manufacturing constraints, a deposition process constraint is added to the optimization problem and its effect on the final design is also tested. [Copyright &y& Elsevier]

Abstract: In micro-electromechanical systems (MEMS), coupling of structures through electrostatic forces is a primordial phenomenon. Simulating the dynamics of MEMS and taking into account such strong coupling effects allows one to predict dynamical performance and stability, and is therefore an essential issue in the design of highly effective and reliable devices. Analysis techniques for such systems require special attention in order to provide to the designer accurate and fast tools. We propose a finite element approach (FEM) that properly handles the strong electromechanical coupling in MEMS. In the simulation example of a micro-bridge, we show that such simulation techniques can reveal complex dynamical behaviors of MEMS such as dynamic pull-in. [Copyright &y& Elsevier]