Home >

news Help

Publication Information


Title
Japanese: 
English:Spontaneous oscillation due to electrical charging effect in MEMS electrostatic switches 
Author
Japanese: Yang-Che Chen, 石田 忠, Hiroshi Toshiyoshi, Rongshun Chen, 藤田 博之.  
English: Yang-Che Chen, Tadashi Ishida, Hiroshi Toshiyoshi, Rongshun Chen, Hiroyuki Fujita.  
Language English 
Journal/Book name
Japanese: 
English:IEEJ Transactions on Sensors and Micromachines 
Volume, Number, Page Vol. 134        pp. 338-349
Published date June 2, 2014 
Publisher
Japanese: 
English:IEEJ 
Conference name
Japanese: 
English: 
Conference site
Japanese: 
English: 
DOI https://doi.org/10.1541/ieejsmas.134.338
Abstract Spontaneous electromechanical oscillation is one of the major causes to shorten the lifetime of MEMS (micro-electro-mechanical systems) contact switches. In this study, we have experimentally visualized the spontaneous oscillation of a MEMS contact switch in the transmission electron microscope (TEM) chamber. We also have studied its behavior by crosschecking with a theoretical analysis based on a multi-physics model implemented on an electrical circuit simulator. Nanoscopic observation and analysis results suggested that a physical mechanism of the spontaneous oscillation is as follows: (i) Upon a voltage application to the actuator electrodes, the contact tips are mechanically brought into contact as an initial condition. (ii) When the voltage is reduced, the tips are retracted and a nanoscale gap is formed between the contact surfaces, where electrical charges are accumulated. (iii) The accumulated charges develop an electrostatic attractive force that pulls back the electrode surfaces into contact again, (iv) thereby instantly neutralizing the charges. (v) The surfaces of the equipotential lose the electrostatic attractive force, leading to the mechanical retraction of the surfaces. As the charges are repeatedly accumulated and dissipated, the electrostatic force is intermittently generated, leading to the cyclic sequence of pull-in, contact, and release that takes place at a fast rate of tens of kHz.

©2007 Tokyo Institute of Technology All rights reserved.