Dynamic pull-in instability and snap-through buckling of initially curved microbeams under the effect of squeeze-film damping, mechanical shock and axial force

Abstract

This research investigates the dynamic behavior of microelectromechanical systems (MEMS) containing curved electrodes, under a combined loading of electrostatic force, axial force, mechanical shock loading and squeeze-film damping (SQFD). The dynamic governing equation of a curved microbeam (micro-arch) is solved by utilizing a nonlinear finite element method, while the effect of the fluid film damping on the microbeam is modeled by the nonlinear Reynolds equation. The response of the micro-arch under different loading conditions and the influence of the MEMS device parameters on its behavior are studied and discussed in detail. In particular, the snap-through and pull-in instabilities of the curved microbeam are thoroughly investigated, and the maximum deflections of the micro-arch subjected to different types of loadings are analyzed. Finally, the phase diagram of the curved beam under various loading conditions is presented for guiding the design and analysis of the MEMS in the future.