Material dielectricity effects on the performance of capacitive micro-devices: a nonlinear study

Abstract

Nowadays, research on the application of new materials with interesting electrical properties, such as high dielectric constant, on electrostatically-actuated microstructures has become one of the prominent research fields worldwide. One of the main disadvantages of these structures is the high required voltage. The main purpose of this paper is to demonstrate the ability of dielectric materials to reduce the required voltage of capacitive MEMS and also to intensify their softening behavior. So, a nonlinear model for a capacitive microstructure has been presented and HfO₂ has been selected as the substrate material of the capacitor whose package is filled with high pressure & dielectric constant gas. It has been shown that both of these changed options together (or each of them) can significantly reduce the required actuating voltage. The physically gradient-descent-based learning method has been used to solve the governing nonlinear equation, allowing to obtain the primary and secondary resonances in the first harmony, as well as in higher harmonies of the response. It has been shown that, growing the thickness of the dielectric layer, as well as using a high coefficient dielectric gas in the package, intensifies the softening behavior.