A simulation study verified by experimental test results for frequency response analysis of MEMS comb-drive resonator

Abstract

This paper presents a finite element method (FEM) simulation study for the frequency response analysis of a capacitive comb-drive resonator based on micro-electro-mechanical systems technology. The post-manufactured design parameters of the resonator are firstly determined after the Modified Silicon on Glass fabrication process by using the parameter extraction method. Then, these results are used to form a 3D structure of the fabricated device. Elmer FEM, an open-source finite element software for multi-physics problems, is selected within the several options for the frequency response analysis of the formed 3D structure. During the FEM analysis, an optimized mesh structure is imported to Elmer FEM for the 3D model of the resonator. Next, the frequency response analyses of the resonator are implemented with a flowchart by using Elmer FEM for a fixed AC level and various DC voltages. The parameter extraction outcomes obtained from probe test data and theoretically calculated values are crosschecked with the output of analyses obtained from the Elmer FEM. The FEM simulation results are compared with the experimental data for the frequency response analyses, the motional parameters and the motional current values as well as the rest capacitance. Furthermore, the approximation error of the simulated results of FEM analysis is calculated. Thus, the capacitive microstructures can be designed more precisely by considering expected quality factor value and fabrication-related deviations.