Design and Strength Analysis of a Novel Silicon-Base MEMS Setback Safety Device With Curved Zig-Zag Tracks

To improve the load identification capability and high overloading-resistibility of the silicon-based micro-electromechanical system (MEMS) setback safety device, a MEMS setback safety device with curved zig-zag tracks as the primary load identification mechanism is designed in this article. The dynamic response of the device under launch and drop load is obtained by the finite element method (FEM) simulation. The result shows that the setback safety device can effectively identify the launch load and distinguish the service load. Moreover, the strength model of the curved zig-zag tracks in the collision is established by the quasi-static method. The strength model is verified by FEM simulation, and the result is highly consistent with the FEM simulation result. The influence of structure parameters on the strength of zig-zag tracks was analyzed. Moreover, the methods to improve the overloading-resistibility of structures with surface collision are given. The impact experiment platform was established by Marchant Hammer and two types of experiments were conducted: 1) multiple impact with increasing load amplitude on a single device and 2) single high amplitude impact on the device. The result shows that the device has sufficient strength while being able to effectively differentiate between drop loads.