Investigation on the Design Method and Failure Mechanism of Silicon-Based MEMS Setback Arming Device

The development of silicon-based microelectromechanical system (MEMS) technology provides a technological path for miniaturization of safety and arming system. Extreme overload condition in the application of artillery fuze poses a challenge for the silicon-based safety and arming system. Research on the design method for silicon setback device with a dynamic response which could effectively distinguish the accident drop and projection is still insufficient. The paper presents a novel structural design for the silicon-based micro-mass spring system which could be used as the setback arming device in artillery fuze. The device is fabricated by using a double-sided ICP etching process. The research of dynamic simulation test on the silicon-based setback arming device is conducted with a Marchette hammer test system and a centrifuge. Results show that there is a mismatching of overload characteristics and dynamic behaviour of silicon-based MEMS setback arming device. On this basis, the design of setback arming device is optimized to visibly present different responses to different high dynamic conditions. LS-DYNA dynamic simulation results show the launching load can be effectively distinguished from the accident drop by the improved design, with a displacement difference ∆D as high as 100 μm is achieved. The setback arming device is successfully interlocked under the projection load of 5000 g with duration time of 1 ms. On the contrary, the setback arming device cannot be interlocked under the accident drop overload of 15,000 g with duration time of 100 μs. The micro mass-spring system returns to its original position after the loading of accident drop. This paper establishes a design method for the setback arming of the silicon-based MEMS micro-mass spring system, which is of great significance to promote the development of miniaturization and intelligentization of artillery fuze.