Research On Dynamic Characteristics And Electrical Properties Of MEMS Microstructures Under High Impact

Compared with macro size mechanical structure,MEMS microstructure based on MEMS technology with small size,low power consumption,low cost,anti-interference,mass production and other advantages are widely used in aerospace,mechanical and electronic fields.Due to the characteristic size of MEMS microstructure in micron order,its mechanics and other properties are very different from macro size.Aiming at the special application demand of high impact,quick response,anti electromagnetic interference,miniaturization and so on,the typical MEMS microstructure was analyzed by MEMS electrical inertia switch which could from amplitude,pulse width of two identification fuze normal emission impact and accidental fall drop impact inertia load.The dynamic characteristics and contact conduction properties of MEMS micro structures under high impact were studied by means of performance test,theoretical analysis and numerical simulation.Firstly,the static and dynamic performance of MEMS electrical inertia switch is tested,and the influence of size effect on performance index and test results is analyzed.Based on strain gradient theory and Hamilton variational principle,the dynamic model of micro beam under high impact is established.Analysis the effect of size effect on deflection,bending stiffness and natural frequency of micro beam under high impact.Modify performance parameters and apply to MEMS electrical inertia switch.The influence of size effect on the dynamic response displacement of MEMS electrical inertia switch detection and identification mechanism and the latching connection mechanism is further analyzed.Based on the observation of the surface topography of MEMS electrical inertia switch,a rough surface adhesion model and contact model,and calculated the corresponding adhesive force.According to the surface morphology,the surface friction and the surface contact conduction electrical properties of the latching mechanism are further analyzed.Finally,systematic analysis of damping in MEMS microstructure under high impact,and the damping delay control method is determined.Numerical simulation of high impact S spring and the MEMS inertial switch modal and transient analysis,the size effect of MEMS inertial switch detecting mechanism and the latching mechanism dynamic displacement response effect,improve the theoretical model.