Simulation based Analysis of Capacitive Pressure Sensor with COMSOL Multiphysics

Abstract

Sensors are omnipresent, being embedded in our bodies, aircrafts, cellular telephones, automobiles, radios, bridges and other innumerable applications such as safety related areas, public and health security systems, smart systems, monitoring applications, biomedical systems, submarines, for underground oil exploration, etc. This paper describes performance analysis of a capacitive pressure sensor working on electro-mechanics interface. Capacitive pressure sensors are advantageous over their counterpart piezoresistive sensors as they consume less power, low sensitivity to temperature, high overpressure capability and high resistance to pressure shocks, improved long term stability, high operating temperature and ease of packaging. In this paper, simulation and performance evaluation of electrical and mechanical effects of MEMS based capacitive pressure sensor with square diaphragm using COMSOL Multiphysics is described. This includes diaphragm deflection, sensitivity and linearity analysis, capacitance vs. pressure analysis and thermal considerations. The values of diaphragm displacement and capacitance are plotted under uniform external pressure 25kPa. The simulation results compare the capacitance values with linearized analytical capacitance under same external pressure. The effect of packaging stress on MEMS design process is also emphasized in the paper. It also describes comparison of sensitivity of capacitive pressure sensor with and without packaging stress.

Barriers for Industrial Sensor Integration Design—An Exploratory Interview Study

“…Unfortunately, RDM research does not yet include mechatronics, such as sensor systems, to a large extent. Instead, and in line with traditional Robust Design approaches, mechatronics design relies heavily on computational parameter optimization [10][11][12] or analytical and numerical analyses of noise factor contributions [13][14][15]. As these approaches are however not suited for early design assessments [16,17], the design of sensor systems usually refers to data sheets.…”