Design and Development of the MEMS-Based High-g Acceleration Threshold Switch

The paper describes the design, simulation and fabrication of a micro-electromechanical system (MEMS) based acceleration threshold switch with an independent angled latching mechanism. The switch is designed to operate in critical applications wherein power cannot be applied. It is a passive device that does not require power for retention of its mechanical state and mechanical memory. The switch consists of a serpentine spring-mass system with an independent angled latching mechanism and multiple contacts. Stoppers were used to limit displacement in the lateral direction and provide a guided path in the line of action to the proof mass. A transient analysis was performed to study non-linear behaviour of the switch. The latching threshold value was determined analytically based on the geometry of the switch. The switch was fabricated on an SOI (silicon-on-insulator) wafer having 25μm thick device layer and 400μm handle wafer. The switch was given a static mechanical shock of 3500g to observe its behaviour under shock. Contact resistance of the switch was approximately 2Ω in the ON position and more than 100 MQ in OFF position. The theoretical and simulated results were in good agreement with the experimental results.