A NOVEL MEMS SHOCK SWITCH WITH MOVABLE CONTACT POINT TO PROLONG THE CONTACT TIME
CAI Hao-gang, DING Gui-fu, Yang Zhuo-qing, ZHOU Zhen-wei, WANG Hong
(Key Laboratory for Thin Film and Microfabrication Technology of Ministry of Education, National Key Laboratory of Nano/Micro Fabrication Technology,Research Institute of Micro/Nanometer Science and Technology, Shanghai Jiaotong University, Shanghai, 200030)
Abstract: A novel shock switch based on the micro-electro-mechanical system (MEMS) for vibration monitoring was designed and fabricated by non-silicon surface micromaching technology, which consists of three 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 modal analysis was carried out showing that the new design reduces the sensitivity to off-axis accelerations compared with the previous design, and the physical parameters was extracted from geometric structure to apply in the Simulink model. Based on the dynamic simulation, the contact-enhancing mechanism was confirmed and compared with the traditional design. The fabricated micro shock switch was tested by dropping hammer experiment. Test results indicate that the threshold acceleration was about 145g and a stable contact time of over 50μs was observed under half-sine wave acceleration with 1ms duration, in agreement with the simulation. The contact effect was improved significantly as expected and the models were able to describe the device behavior correctly.