Peng Yingchun, Wen Zhiyu, Li Dongling, Shang Zhengguo
Microsystem Research Center, Chongqing University, Chongqing 400044, China.
Key Laboratory of Fundamental Science of Micro/Nano-Device and System Technology, Chongqing University, Chongqing 400044, China.
Micromachines (Basel). 2016 Dec 20;7(12):237. doi: 10.3390/mi7120237.
Squeeze-film damping and acceleration load are two major issues in the design of inertial micro-switches. In order to deeply and systematically study these two issues, this paper proposes a typical vertically-driven inertial micro-switch, wherein the air and electrode gaps were chosen to design the required damping ratio and threshold value, respectively. The switch was modeled by ANSYS Workbench, and the simulation program was optimized for computational accuracy and speed. Transient analysis was employed to investigate the relationship between the damping ratio, acceleration load, and the natural frequency, and the dynamic properties (including contact bounce, contact time, response time, and threshold acceleration) of the switch. The results can be used as a guide in the design of inertial micro-switches to meet various application requirements. For example, increasing the damping ratio can prolong the contact time of the switch activated by short acceleration duration or reduce the contact bounce of the switch activated by long acceleration duration; the threshold value is immune to variations in the damping effect and acceleration duration when the switch is quasi-statically operated; the anti-jamming capability of the switch can be improved by designing the sensing frequency of the switch to be higher than the acceleration duration but much lower than the other order frequencies of the switch.
挤压薄膜阻尼和加速度负载是惯性微开关设计中的两个主要问题。为了深入系统地研究这两个问题，本文提出了一种典型的垂直驱动惯性微开关，其中分别选择空气间隙和电极间隙来设计所需的阻尼比和阈值。利用ANSYS Workbench对该开关进行建模，并针对计算精度和速度对仿真程序进行了优化。采用瞬态分析来研究阻尼比、加速度负载和固有频率之间的关系，以及开关的动态特性（包括接触弹跳、接触时间、响应时间和阈值加速度）。这些结果可为惯性微开关的设计提供指导，以满足各种应用需求。例如，增大阻尼比可以延长由短加速持续时间激活的开关的接触时间，或者减少由长加速持续时间激活的开关的接触弹跳；当开关准静态工作时，阈值不受阻尼效应和加速持续时间变化的影响；通过将开关的传感频率设计得高于加速持续时间但远低于开关的其他阶次频率，可以提高开关的抗干扰能力。
