Methods for Protection of Silicon Suspensions from High Shock Loading

⎯ There are many areas which require instruments to be operational after exposure to high levels of shock acceleration such as planetary missions, oil drilling, and military applications. MEMS devices are typically quite resilient to low shock due to their small mass and high resonant modes. Problems can arise, however, when devices with low resonant frequencies and large ranges of motion are placed under high shock loading. This work presents various methods and experimental results on surviving high shock loading for 10 Hz silicon suspensions with 100’s of μm of lateral travel, for use in a microseismometer. Electrostatic clamping and mechanical latching are both analyzed for their effectiveness in shock protection. A method involving a sublimating substance used to encapsulate the suspensions completely during deployment is also presented, and furthermore shown to survive shocks in excess of 10,000g.