Variation of Sensitivity of a MEMS Capacitive Accelerometer Based Microphone with Suspension System Topology

Abstract

The present research seeks to improve a highly sensitive MEMS capacitive accelerometer as a probable completely implantable hearing aid microphone. The research analyses the effect of different suspension system topologies on accelerometer efficiency. The topology of folded beam suspension is considered to be the most suitable for the proposed system. The design factors such as weight, height and resonant frequency are considered to make the accelerometer an effective biomedical system which can be completely implanted with COMSOL MULTIPHYSICS 4.2 the optimized system is simulated and validated. The accelerometer occupies 1mm2 of sensing area and achieves a nominal capacitance of 5.30 pF and an optimized capacitive sensitivity of 6.89fF.