Latching in a MEMS shock sensor: Modeling and experiments

Modeling, numerical, and experimental efforts undertaken to develop a fundamental understanding of latching in a MEMS shock sensor are presented. A two degree-of-freedom model is developed and numerical studies are conducted with this model. These studies, which help shed light on difficult to observe experimental aspects, are used to examine the interaction forces between the shock sensor mass and latch, bounce effects, and loss of contact between the mass and the latch. High-speed video images of the shock sensor motions collected during a latching event are shown, and these results are used to verify the model predictions. Parametric studies conducted to examine the sensitivity of the design to friction and the effects of the latch mass and stiffness properties on the latch bounce are presented and discussed.