Silicon-based, low-g microelectromechanical systems inertial switch for linear acceleration sensing application

Most of the microelectromechanical systems inertial switches developed in recent years are intended for shock and impact sensing above 40 g. These switches are fabricated based on non-silicon surface micromachining with multiple steps of electroplating. In this reported work, a silicon-based low-g inertial switch typically used for linear acceleration sensing was conceived, designed and fabricated. The developed inertial switch consists of a high volume proof mass and low stiffness spiral spring, and is fabricated in a specially designed double-buried layer silicon-on-insulator wafer, with standard silicon micromachining. The measurement results show that the threshold value is about 7.42 g and the stiffness is about 1.5 N/m, in accordance with the finite element method calculation.