Dynamic Analysis of Viscoelastic Circular Diaphragm of a MEMS Capacitive Pressure Sensor using Modified Differential Transformation Method

Abstract

In this paper, a dynamic analysis of the viscoelastic circular diaphragm of a Micro-Electro-Mechanical System (MEMS) capacitive pressure sensor using the Modified Differential Transformation Method (MDTM) is presented. The MEMS technology has been increasingly used to fabricate sensors and actuators and the MEMS capacitive pressure sensor is emerging in many high-performance applications. The deflection of these sensors diaphragm (plate) depends largely on the material of the diaphragm. In this study, a circular diaphragm of viscoelastic material is modeled using the classical plate theory. The governing differential equation is solved using Modified Differential Transformation Method (MDTM) and the result is validated with Finite Difference Method (FDM). The result shows excellent agreement with the numerical method. The effects of amplitudes, frequency, viscoelastic parameter, and time of applied pressure on deflection of the viscoelastic circular diaphragm are investigated. It is established from the results that the deflection of the sensor increases with an increase in the amplitude, frequency and time of the applied pressure. In addition, an increase in the viscoelastic parameters resulted in an increase the deflection of the diaphragm which consequently increases the capacitance and sensitivity of the sensor. Hence, the viscoelastic circular diaphragm of the MEMS capacitive pressure sensor exhibits better sensitivity performance when compared with that of elastic material. Finally, the Modified Differential Transformation Method applied in obtaining the solution of the developed model is effective in predicting sensor characteristics. The study will enhance the design of MEMS capacitive pressure sensor with viscoelastic circular diaphragm.