Nonlinear dynamics of multilayered circular microplate under electrostatic actuation

In this paper we investigate the static and dynamic behavior of an electrically actuated multilayered circular microplate. The dynamic analogue of Von Karman equation is used to model the governing equation of microplate which accounts for different sources of nonlinearities. We employ a multi-mode reduced order model (ROM) of the governing equations based on Galerkin discretization method to solve for governing and compatibility equations. The eigenvalue problem associated with the governing equation is solved numerically for first few natural frequencies and modeshapes. The microplate is then loaded with direct voltage (DC) load until instability phenomena known as static pull-in is observed. Then, the dynamic forced vibration is investigated by actuating the device with DC voltage superimposed by a small AC voltage. We investigate the transition from hardening to softening behavior near primary resonance for a combination of static and dynamic loads. A MEMS device is fabricated from a polyimide layer coated with metals from top and bottom to validate the theoretical simulation results with the experimental results. The simulated theoretical results are in good agreement with the experiments