A robust micro mechanical-latch shock switch with low contact resistance

Here a robust micro mechanical-latch shock switch is presented to record shock event for tens of G without slippage effect. Since the proposed shock switch is made of Ni, low contact resistance can be easily achieved to simplify sensing circuit. An analytical model with fixed-roller boundary condition is developed to investigate the effects of key dimensional parameters. The experimental results show that the switch can be successfully latched after experiencing a maximum downward shock of 17.22 G, which agrees well with the simulated threshold level of 17 G. Furthermore, even after applying 50 G opposite pulse acceleration, the switch can still remain latched due to limited space under the movable part. The contact resistance after latching is found to be around 40Ω, six orders less than the resistance before latching. These results verify the accuracy of the analytical model and the robustness of the proposed micro shock switch design to provide low contact resistance at compact device size.