Effect of Micro Lever Width on the Mechanical Sensitivity of a MEMS Capacitive Accelerometer

The paper presents a MEMS capacitive accelerometer using microlevers as a suspension system. The microlevers serve to amplify the output displacement of the accelerometer and hence increase the mechanical sensitivity of the device. A novel accelerometer design is presented in the paper to be used as a transducer for a totally implantable hearing application. The design considerations for surgical implantation of the accelerometer on the middle ear bone umbo are followed in selecting the dimensions of the accelerometer. The impact of the width of a micro lever on the displacement of the accelerometer is considered, and an analytical model including a correction factor is developed. The proposed accelerometer is designed and simulated in COMSOL MULTIPHYSICS 4.2. The developed analytical model is validated by comparing with the COMSOL simulation results. The mechanical sensitivity of the accelerometer with and without considering the effect of microlever width is compared. The enhanced mechanical sensitivity of 2.60 nm/g is obtained.