通过可动触点延长接触时间的新型微冲击开关

A novel mems shock switch with movable contact point to prolong contact time

基于非硅表面微加工技术,设计并制造了一种用于振动监测的新型微机电系统(MEMS)冲击开关。开关主要由三部分构成:作为可动电极的质量块,作为固定电极的十字梁,和位于质量块中心的具有延时作用的可动触点。通过ANSYS有限元仿真,对器件进行模态分析,考察了器件的横向抗干扰能力;并提取了器件的物理参数(如弹簧弹性系数和系统有效质量),以用于Simulink动态仿真。通过动态仿真验证了器件的工作原理,并与传统微冲击开关进行了比较。使用落锤试验对所制造出的微冲击开关进行测试,加载脉宽1ms的半正弦冲击加速度,测得其阈值约为145g,并且接触时间可稳定在50μs以上。测试结果与仿真符合较好,证明了新型设计可以有效地增强接触效果,所建模型可以较准确地描述器件的动态响应。

A novel shock switch based on a micro-electro-mechanical system(MEMS)for vibration monitoring was designed and fabricated by non-silicon surface micromaching technology.It consisted ofthree main parts:the proof mass as the movable electrode,the cross beam as the stationary electrode and the movable contact point to prolong the contact time.The ANSYS model was built,by which the nodal analysis was carried out showing that the new design reduced the sensitivity to off-axis accelerations compared with the previous design,and the physical parameters were extracted from the structure so they could be used in the Simulink model.Through the dynamic simulationn,the contact-enhancing mechanism was verified and compared with the traditional design.The fabricated micro shock switch was tested with a dropping hammer experiment.Test results indicated that the threshold acceleration was about 145g and a stable contact time of over 50μs was observed under a half-sine wave shock load acceleration with 1 ms duration,in agreement with the simulation re-sults.The contact effect was improved significantly as expected and the proposed model was able to describe the device's behavior correctly.