Design and Parametric Analysis of the Threshold-Value Judging Mechanism in MEMS Security System

In this paper, a MEMS security system has been proposed. The size of the device is 10mm×13mm×0.5mm. The role of the threshold-value judging mechanism is to ensure the safety in handling transportation and storage, and reliable firing with the launch overload. Through establishing the three-dimensional model of the threshold-value judging mechanism, establishing the force and the parameters of the threshold-value judging mechanism, deriving the mathematical model according to the variable cross-section cantilevered beam stress theory, establishing the finite element model by using ANSYS/LS-DYNA and carrying out the centrifugal test. Simulation and test results match theoretical results quite well. Appropriate threshold-value judging mechanism is designed to meet two items, one item is threshold node can reliably release slider when the centrifugal acceleration is more than 30000g (g=10m/s ² ); the other item is the threshold node can effectively restrict the slider to ensure the safety of the device when primary insurance accident arming in handling transportation.