Deflection amplification mechanism in a capacitive accelerometer

This work presents a novel mechanical deflection amplification mechanism to improve the performance of MEMS inertial sensors. The mechanism applies the leverage principle by employing microlevers to enhance motion. To demonstrate the operation of the mechanism a deflection amplifier with an amplifying factor of 40 was implemented in a single axis capacitive accelerometer. The deflection of the accelerometer is enhanced by the amplification factor of the amplifier thus providing a larger capacitive signal to the pick off circuit. This scheme aims to increase the signal-to-noise-ratio of sensors without introducing additional electronics to the system. The sensor has been successfully fabricated in a SOI based process. Results from its evaluation, presented in this paper reveal the effectiveness of the mechanism.