Modeling of Square ZnO Nanomembrane with Two Types of Cavities: Vacuum Cavity and Graphene Cavity Using Comsol Multiphysics Software: The Case Study MEMS Capacitive Pressure Sensor*

We propose the modeling of Micro-Electro-Mechanical Systems (MEMS) capacitive pressure sensor. Two kinds of Nano-membranes were investigated. Mainly ZnO/Vacuum/SiO₂/Si and ZnO/Graphene/SiO₂/Si capacitive sensors were studied using COMSOL Multiphysics. Capacitance, deflection versus pressure for various membrane thicknesses were modeled and simulated using Finite element method (FEM). The total, average, and maximum deflection as a function of applied pressure were studied. We found that deflection increases as the applied pressure is increased. The average displacement, total displacement, mechanical sensitivity and capacitance sensitivity for both cavities were found to be the same. However, the capacitance of the capacitor formed using graphene cavity is larger than that of the capacitance obtained using vacuum cavity. Our results could be used as guides to design such novel capacitive sensors.