Bistable devices
Mechanical bistable beams can be used as MEMS shock sensor. A practical way for producing a bistable element is to couple two doubly clamped beam with a deformed initial shape, as shown in the figure
Simplified scheme: rigid shuttle and bistable element.
SEM of a MEMS shock sensor based on bistable beams.
When an external acceleration reaches a given threshold (say 1000g for the device designed, where g is the acceleration of gravity), the contact force transmitted by the mass to the bistable element induces the transition to a second stable configuration. During the dynamical transition the beam hits a weak link that breaks and opens a resistive path.
Zoom on the bistable element in the two stable configurations before and after actuation.