Design and contact dynamics simulation of an inertia micro-switch based on non-silicon substrate

A multi-layer structural inertia micro-switch with conjoined snake springs has been designed based on non-silicon substrate. The micro-switch consists mainly of a suspended thick proof mass as a movable electrode, and an elastic beam with holes as a fixed electrode that is some distance above the proof mass. This conformation benefits the protection of the switch against severe shock damage. The relationship between threshold acceleration and proof mass thickness H of the micro-switch has been investigated by theoretical analysis and finite element simulation. It is suggested that the micro-switch with H=50mum generally fulfils the expected 50g threshold. The dynamic contact simulation of the micro-switch has been implemented under the half-sine wave shock with 50g peak value, and its response time is about 0.22ms.