Design and modeling of curved beam based differential capacitive MEMS accelerometer

Abstract

This work presents the design and modeling of micro-electro mechanical system (MEMS) accelerometer with curved beams as the suspension springs. Initially, we explore the mechanics of curved micro beams to find their natural frequency. Linear frequency analysis of curved beams have shown that as the radius of the curvature increases, the natural frequency decreases due to increase in the flexibility. Further, we utilized the curved micro beams as the suspension springs to design a MEMS accelerometer with differential capacitive sensing mechanism in MEMS+ software. The dominant in-plane mode of oscillation with natural frequency of 7.98 kHz has been considered for the modal, and electromechanical analysis. The obtained results have shown that the accelerometer has maxium mechanical, and capacitive sensitivity of 0.0308 μm/g, and 27.211 fF/g respectively., for the radius of curvature of 2000 μm.