MEMS dual axis accelerometer with H-T shape structure

Abstract

MEMS accelerometers have been used in air bag deployment system and other applications. Most MEMS accelerometer devices are sensitive to acceleration input along one direction. In this paper, a dual-axis MEMS accelerometer which can simultaneously measure acceleration inputs along X and Y directions is proposed. The proposed MEMS accelerometer utilizes two sets of folded beams perpendicular to each other to sense acceleration inputs along X and Y directions within the device plane. The working principle of the dual-axis MEMS accelerometer is analyzed. A theoretical model is developed to predict the performance of the accelerometer. A set of example design parameters of the device is obtained based on the analysis. ANSYS simulation is used to verify the function of MEMS accelerometer. The fabrication flow of the MEMS accelerometer is suggested. Combined with a Z-axis accelerometer, the proposed dual-axis MEMS accelerometer can be used for acceleration measurement along complete X, Y and Z directions for 3D inertial navigation system.