The Design and Analysis of Universal Inertial Switch Based MEMS

In this paper, a novel MEMS inertial switch is designed and characterized for the purpose of crash sensing for ammunition systems in which high-speed response is required for triggering the detonator. In order to keep the same sensitivity in different direction, the structure of an annular proof-mass suspended by four serpentine flexures is designed. The switch can be integrated with electronics, fast-acting，and lack of a requirement for continuous power, and can be used in a wide area. The motion of the inertial switch is analyzed by dynamic simulation under the 700g threshold acceleration in y direction, the simulation results show that the response time is 0.142ms and the contact time of the switch is about 5 , it illustrates that the response time is short enough and the impact time satisfy the ask. The von-mises stress of the structure is calculate, the maximum stress occurs in the serpentine flexures, the value is 60.61 MPa, much less than the yield strength of the silicon, the switch can be used time after time.