Design and Analysis of Wet Etching Based Comb Type Capacitive Accelerometer

Abstract

A wet etching based tilted comb type microaccelerometer has been proposed. This paper deals with the analytical estimation of sensitivity and operating frequency of this oriented silicon-based accelerometer. The mechanical and electrical behaviour of the structure have been simulated by Finite Element Method (FEM) by using Intellisuite 6.1 software. Static, modal and dynamic simulations were done. The theoretical and simulated results are compared and found in reasonable agreement. The sensitivity of the structure is found to be ~21 fF/g with a first resonant frequency 843 Hz of twisting mode. The Von Misses stress analysis was done for the beam region. Bandwidth of the structure was found to be 70 Hz for the accelerometer using a 15 mm deep pit in a glass mount.

Keywords

• Tilted comb type accelerometer
• angle of twist
• Von Misses stress
• Bandwidth