Symmetry breaking oscillations in electrostatic MEMS under superharmonic excitation

Microelectromechanical systems (MEMS)-based vibratory structures have become popular due to their simple fabrication processes, high quality factors, low loss and high sensitivity. Applications of such devices as sensors require a proper understanding of their operational characteristics in various regimes. This work is a study of the dynamics of an electrostatically actuated MEMS doubly-clamped beam under superharmonic excitation from a qualitative point of view whereby the nonlinear dynamic response of such devices can be analyzed to some extent. Here, we report some phenomena which we have come across during our measurements of the MEMS device under consideration and attempt to explain our findings through some intuitive analysis.