Pull-in characteristics of electrically actuated MEMS arches

This paper examines the pull-in characteristics of initially curved microelectromechanical resonators actuated by a DC voltage along with an AC harmonic voltage. The deformable electrode is modeled by means of a clamped-clamped Euler-Bernoulli microarch in which a combination of mechanical, electrostatic, and electrodynamic nonlinearities are taken into account. A high-dimensional reduced-order Galerkin model is built, and the effect of various system parameters on pull-in instabilities is investigated numerically. Specifically, the electroelastostatic deformation as well as pull-in instabilities are analyzed for the cases actuated electrostatically via the DC voltage; the DC voltage deflection characteristics due to the simultaneous presence of mechanical and electrical nonlinearities are presented. The electroelastodynamic deformations are investigated for the system under simultaneous actuation of the DC and AC voltages; the AC frequency-motion as well as the AC amplitude-motion curves is analyzed to highlight the effect of electroelastodynamic nonlinearities.