Bistable nonlinear response of MEMS resonators

This study, for the first time, investigates the nonlinear bistable response of electrically actuated initially imperfect viscoelastic microresonators under DC and AC actuations, while including fringing field effects and retaining both longitudinal and transverse motions. The modified version of the couple stress theory, the Kelvin–Voigt material, and the Meijs–Fokkema electrostatic formula are employed in order to develop a multi-physics model of the electrically actuated initially curved microresonator while accounting for the effects of geometrical nonlinearities, damping nonlinearities, fringing field, small size, and residual axial load. The developed continuous multi-physics model is reduced to set of differential equations of ordinary type, which are nonlinearly coupled, employing a weighted residual method and solved numerically making use of a continuation technique. The numerical simulations results are shown via plots of static deflection and natural frequency versus the DC voltage as well as plots of motion amplitude versus the AC frequency.