Failure analysis and optimization of silicon-based MEMS setback safety device

To enhance the load identification capability and overload resistance of the silicon-based MEMS setback safety device, a silicon-based MEMS setback arming device research is carried out based on the parallel-axis ammunition fuze. Firstly, based on the spring-mass block system theory, the displacement response of the setback safety device was analyzed. A Machette Hammer platform and a visualization test platform were established. Three typical direction impacts were tested on the setback safety device prototype to determine the lack of overload resistance. An improved setback safety device is proposed by introducing a fixed anchor point to constrain the lateral displacement of the mass. A comparative analysis of displacement response and stress distribution in the tooth mechanism between the original and improved devices was conducted by finite element simulation. The results demonstrate that the fixed anchor point configuration effectively enhances device performance. Finally, the enhanced prototype was fabricated using the deep reactive ion etching (DRIE) process, followed by testing for validation. Test results demonstrate significantly enhanced overload resistance in the modified device: Withstood multiple high-intensity shocks along the setback direction before function failure, while exhibiting no significant damage under lateral and reverse setback direction impacts. The results of this paper can provide a reference for the failure analysis and optimization of similar silicon-based MEMS setback safety devices.