Finite Element Analysis of Graphene Oxide Based Nanoelectromechanical Capacitive Switch

Abstract

The present work deals with finite element analysis (FEA) of a novel configuration of double clamped nanoelectromechanical (NEM) capacitive switch. Graphene oxide (GO), a graphene derivative has been used as suspended beam material in NEM switch for the first time. In the proposed work, GO is used as dielectric material having negative Poisson’s ratio value. The variation in capacitance has observed as the beam is pulled down by the actuating electrode. Analysis of pull-in voltage and von Mises stress are done using COMSOL Multiphysics, for standard and perforated GO NEM switch structures. The actuation voltage of 5.4 V for standard beam structure and 3.35 V for perforated beam structure have been achieved for the beam length of 1µm and width of 0.3 µm. The actuation voltage and von Mises stress value have reduced by making perforations in the beam. The comparative analysis of graphene and GO NEM switches have also been done in terms of von Mises stress to ensure the mechanical reliability. The von Mises stress values for GO NEM switch and graphene NEM switch are 500 MPa and 4.8 GPa respectively. This lesser value of von Mises stress in GO NEM switch makes it a good choice as beam material. The capacitive switch is demonstrated for standard and perforated beam structures. The variation in capacitance has observed as the beam is pulled down by the actuating electrode and at actuation voltage, the maximum value of capacitance obtained is 0.9403 pF.