Micro-cantilever shocking-acceleration switches with threshold adjusting and 'on'-state latching functions

• Published in: Journal of micromechanics and microengineering Vol. 17; no. 3; pp. 567 - 575
• Main Authors: Jia, Mengjun, Li, Xinxin, Song, Zhaohui, Bao, Minhang, Wang, Yuelin, Yang, Heng
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.03.2007; Institute of Physics
• Subjects: Applied sciences; Circuit properties; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Physics; Precision engineering, watch making; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Threshold switching; Pull in voltage; Capacitive transducer; Bulk micromachining; Experimental study; Cantilever beam; Microrelay; Step response; Bandwidth; Microwave circuit; Frequency response; Selector switch; Microelectromechanical device; Electrostatic force
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/17/3/020

A micromechanical shocking-acceleration switch is developed. By using electrostatic force combined with the dynamic shocking force, the switch features a threshold adjustable capability. Besides, an electrostatic pull-in phenomenon is used to enable the switch an 'on'-state latching ability. The former facilitates individual applications and can compensate for the threshold inaccuracy from fabrication tolerance. The latter can keep the switch at the 'on'-state even after the shock disappears. Theoretical analysis is carried out for the step shocking response, with the response frequency bandwidth taken into consideration. Then the switch of the 1000-5000 g measure range is designed, simulated with Coventor-ware and micro-fabricated using bulk micromachining technologies. Both the threshold adjusting and the 'on'-state latching functions of the micromechanical shock switch are verified by using a dropping hammer experiment. The tested data generally have an agreement with the simulated results. Even so, the slight difference between the simulation and the tested results is discussed.