title: Design and Optimization of a Stationary Electrode in a Vertically-Driven MEMS Inertial Switch for Extending Contact Duration.
abstract: A novel micro-electro-mechanical systems (MEMS) inertial microswitch with a flexible contact-enhanced structure to extend the contact duration has been proposed in the present work. In order to investigate the stiffnesskof the stationary electrodes, the stationary electrodes with different shapes, thicknessh, widthb, and lengthlwere designed, analyzed, and simulated using ANSYS software. Both the analytical and the simulated results indicate that the stiffnesskincreases with thicknesshand widthb, while decreasing with an increase of lengthl, and it is related to the shape. The inertial micro-switches with different kinds of stationary electrodes were simulated using ANSYS software and fabricated using surface micromachining technology. The dynamic simulation indicates that the contact time will decrease with the increase of thicknesshand widthb, but increase with the lengthl, and it is related to the shape. As a result, the contact time decreases with the stiffnesskof the stationary electrode. Furthermore, the simulated results reveal that the stiffnesskchanges more rapidly withhandlcompared tob. However, overlarge dimension of the whole microswitch is contradicted with small footprint area expectation in the structure design. Therefore, it is unreasonable to extend the contact duration by increasing the lengthlexcessively. Thus, the best and most convenient way to prolong the contact time is to reduce the thicknesshof the stationary electrode while keeping the plane geometric structure of the inertial micro-switch unchanged. Finally, the fabricated micro-switches with different shapes of stationary electrodes have been evaluated by a standard dropping hammer system. The test maximum contact time under 288 g acceleration can reach 125 µs. It is shown that the test results are in accordance with the simulated results. The conclusions obtained in this work can provide guidance for the future design and fabrication of inertial microswitches.
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. xuqiu@sjtu.edu.cn.
authors.forename: Qiu
authors.initials: Q
authors.lastname: Xu
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. yzhuoqing@sjtu.edu.cn.
authors.forename: Zhuo-Qing
authors.initials: ZQ
authors.lastname: Yang
authors.affiliation: Huaihai Industrial Group Co., Ltd., Changzhi 046012, China. fuhbo_406@163.com.
authors.forename: Bo
authors.initials: B
authors.lastname: Fu
authors.affiliation: Huaihai Industrial Group Co., Ltd., Changzhi 046012, China. baoyanping304@163.com.
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Bao
authors.affiliation: Huaihai Industrial Group Co., Ltd., Changzhi 046012, China. df11g25t@126.com.
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. Cecilia_Sun@sjtu.edu.cn.
authors.forename: Yun-Na
authors.initials: YN
authors.lastname: Sun
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. zhaomy@sjtu.edu.cn.
authors.forename: Meng-Yuan
authors.initials: MY
authors.lastname: Zhao
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. lijian19930405@126.com.
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. gfding@sjtu.edu.cn.
authors.forename: Gui-Fu
authors.initials: GF
authors.lastname: Ding
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. xlzhao@sjtu.edu.cn.
authors.forename: Xiao-Lin
authors.initials: XL
authors.lastname: Zhao
keywords: contact time; geometrical parameters; inertial micro-switch; stationary electrode; surface-micromachining