Comparison of geometric and drive-induced nonlinearities in doubly clamped, thermoelastic nanoelectromechanical systems

Abstract

The performance of resonant sensors based on nanoelectromechanical systems depends critically on themaximum amplitude of oscillation reached in the linear regime. The maximum linear amplitude is determined bynonlinear mechanisms that can originate from the material, geometric and transduction mechanism related factors. Herewe compare the two competing effects, the geometric and drive-induced nonlinearities, for a commonly used device family,the thermoelastically driven, doubly clamped beams. We find that the geometric nonlinearity dominates for most of thedevice designs used in the literature, however the drive-induced nonlinearity becomes the determining factor for thickerbeams with small electrode lengths.