一种具有高抗侧向过载的垂直敏感弹载MEMS惯性开关

A Vertical Sensitive Missile-borne MEMS Inertial Switch with High Shock-Resistibility to Lateral Overload

提出了一种具有高抗侧向过载能力的MEMS惯性开关,其结构简单且可以敏感垂直方向上的加速度冲击。开关中引入了阿基米德螺旋线式弹簧结构,当有较大的侧向冲击作用在器件上时,质量块不会发生较大幅度的侧翻位移,从而防止开关误触发并延长器件的使用寿命。应用COMSOL有限元软件对惯性开关的动态响应过程进行了仿真,结果表明,在高侧向冲击下,质量块仅发生极小幅度的侧翻。随后,利用非硅表面微加工工艺对设计的惯性开关进行了制作,并通过落锤系统对样品进行了性能测试。测试结果表明,所制作的MEMS惯性开关在垂直敏感方向上的阈值加速度为237 g,接触时间为320μs;当施加8750 g的侧向冲击时,开关器件未被误触发,且器件未被损坏,所设计制作的MEMS惯性开关表现出良好的抗侧向过载性能,将为器件在复杂环境下的实际应用提供重要技术参考。

This paper proposes a MEMS inertial switch with high shock-resistibility to lateral overload, which has a simple structure and can be sensitive to acceleration shocks in the vertical direction. The Archimedes spiral springs are introduced into the device. When a large lateral shock is applied to the switch, the proof-mass would not rotate or flip,thereby prolonging its service life and having the ability of anti-false triggering. Dynamic response of the designed inertial switch is simulated by COMSOL finite-element software, and the results show that the proof-mass only rotates at a small angle under high lateral shock. The designed inertial switch is fabricated using non-silicon surface micromachining technology and then tested through the dropping hammer system. Experimental results show that the manufactured device has a threshold acceleration of 237 g in the vertical direction and the contact time is 320 μs. When a lateral shock of 8750 g is applied to the device, the switch is not triggered by mistake and could still operate normally. Therefore, the designed MEMS inertial switch shows high shock-resistibility to the lateral overload. This design will provide an important reference for these kinds of devices that would be used in complicated practical applications environments.