Design and Analysis of General Purpose MEMS Accelerometer

Abstract

Inertial sensors including accelerometers and gyroscopes play an important role in vibration sensing, health monitoring, automotive applications etc. Here we design, fabricate and characterize the set of accelerometers with natural frequencies varying from 8 to 18 kHz. The design is compatible with PolyMUMPs process and has an ease of integrability with the electronic circuits. The operating voltage of the sensor is less than 3.5 V and both the structural and electrode layers are in polysilicon. The user is given an option of choosing the accelerometer in terms of sensitivity and the working range of g (acceleration due to gravity) based on the need of the application. Analytical, Numerical and experimental studies are carried out to determine the sensitivity, frequency range, maximum measurable acceleration and the pull-in voltage of each device. Effect of residual stress on the static and dynamic response characteristics of the accelerometer has been explored and the effect of same on its sensitivity.