Global Dynamics of MEMS Resonators under Superharmonic Excitation

We present a methodology to simulate the transient and steady-state dynamics of microbeams undergoing small or large motions actuated by combined DC and AC loads. We use our methodology to simulate the dynamics of MEMS resonators excited near half their fundamental natural frequencies (superharmonic excitation). We present results showing the effect of varying the DC bias, the damping, and the AC excitation amplitude on the frequency-response curves. Weshow that the dynamic pull-in phenomenon can occur for a superharmonic excitation at an electric load much lower than that predicted based on static analysis.