Special Issue on Micro-Machine
Toshio Fukuda* and Hidemi Hosokai**
*Faculty of Engineering, Nagoya University
**Faculty of Engineering, Science University of Tokyo
Much attention has been paid to the micronization of machine systems founded on the silicon-based semiconductor technology which are greatly different imagewise from the conventional machines. As a result, studies are being actively carried out on micro-machines. In addition, studies on extremely micro actuators and sensors based on the conventional precision processing techniques are also being conducted. These techniques have begun to support studies and developments of micro-robots which are based on new concepts of machine systems. The following techniques may be contained in the basic technology of micro-robots: 1) Micro-mechanical device techniques; 2) Micro-sensor and control circuit techniques; 3) Systems techniques; 4) Measurement and evaluation techniques A micro-robot as the totally integrated system of these techniques is considered for use in various fields including medical treatments and industrial areas. For applications in the medical field, micro-robots may be used in microsurgery, micro-operation, and micro-capsuling, while for industrial applications, micro-robots may be employed in the areas of maintenance, manufacturing, public well-being, and construction, among others. Nevertheless, in order to develop components in the truly micro-mechanical realm, to further refine these techniques and then to complete a micro-robot, system components such as sensors, actuators, processors, energy sources, functional parts, and communications devices are essential. Recently, the techniques for precision processing of silicon have made remarkable progress; in consequence, close attentions are being paid to micro-machining whereby silicon substrates are processed cubically by means of these processing techniques to form cubically structured function al elements. Micro-machining enables surfaces to be processed without producing scratches, thereby making it possible to create mechanical elements having wide dynamic ranges. Micro-processors and micro-actuators enjoying these advantages are beginning to be created on silicon substrates. Against this background, the present special issue on micro-machine systems has been planned to provide a glance at how the micro-related technology in micromachines and micro-mechanisms has advanced thus far and also at what course the future development of this technology will follow or how it will affect the surrounding areas of the technology. In the beginning, discussions on micro-mechanisms, micro-sensors, and micro-actuators were provided by Dr. Teru Hayashi (Tokyo Institute of Technology), Osamu Tabata and Susumu Sugiyama (Toyoda Central Research Center, Inc.), Kohji Kajimura (Electrotechnical Laboratory), and Toshi Takamori (Kobe University). In the subsequent sections, Dr. Masayoshi Ezashi (Tohoku University), Toshio Fukuda, Motohiro Fujiyoshi, Fumihiro Arai, Hideo Matsuura (all of Nagoya University), Toshiro Higuchi (University of Tokyo), Minoru Sakata, Katsumi Hosoya, Masatoshi Oba, Masao Hirano (all of OMRON Corp.), Katsuyoshi Kuribayashi (Yamaguchi University), Yoshitaka Tatsue and Tokio Kitahara (both of Mechanical Engineering Laboratory) gave explanatory introductions of their research activities. At the same time, Dr. Kohji Ikuta (Kyushu Institute of Technology), Kinji Harada and Hideki Kuwayama (both of Yokogawa Electric Corp.) provided the news concerning the developments of their micro-machines. Moreover, the latest information on micro-machines was presented by Dr. Tadashi Kitamura and Mochimitsu Komori (both of Kyushu Institute of Technology). 1 hope you will find some useful articles for understanding the state of art and the direction of the future developments.