Positioning Characteristics of a MEMS Linear Motor Utilizing a Thin Film Permanent Magnet and DLC Coating
Ryogen Fujiwara*, Tadahiko Shinshi*, and Minoru Uehara**
*Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
**Hitachi Metals, Ltd., 2-15-17 Egawa, Shimamoto-cho, Mishima-gun, Osaka 618-0013, Japan
A high performance Nd2Fe14B/Ta thin film Permanent Magnet (PM) not only has a high remnant flux density and a high coercive force similar to those of a conventional sintered Nd2Fe14B magnet, but also has a high heat tolerance. Using a thin film PM, we developed a moving-magnet typeMEMS linearmotor consisting of a silicon slider including a multi-pole magnetized thin film PM, a linear guideway made from silicon, and a two-phase micro-coil. Diamond-Like Carbon (DLC) coatings were used in order to reduce the friction force between the slider and the guideway. The purpose of this study is to realize feedback positioning of the MEMS linear motor and to investigate the dynamics of the linear motor system. In a driving experiment, the minimum current and voltage to start the slider were less than 0.26 A and 0.6 V, respectively. In positioning tests, the positioning resolution and bandwidth were 100 µm and 54 Hz, respectively.
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