SUMMARY AND CONCLUSIONS

This brief survey of microactuator work in Japan can be summarized as follows.

1. The development of microactuators is still in a relatively early phase -- a stage that makes it appropriate to support study of a wide range of approaches. This is an observation shared in the United States and Japan, but there is even wider diversity in the types of actuators under consideration in Japan than in the United States.

2. A particularly interesting prime mover that has applications both to mini- and microactuators is based upon piezoelectric materials used both for positioning and for ultrasonic motors. Success in this field is based on control of material properties. Present practice in Japan is well ahead of that in the United States.

3. Electrostatic actuation is widely used for diverse purposes. It is recognized as especially convenient when IC-compatibility is demanded. U.S. research on electrostatic actuation appears to be leading that of Japan.

4. Japanese expertise in the design of small electromagnetically-driven motors has enabled shrinkage of these elements to millimeter dimensions. This size appears to be near the limits of practicality for miniaturization by the downsizing of conventional machining. In the less than 100 micron realm, electromagnetic (EM) drive is under study in both the United States and Japan, and there appears to be a slight edge in the work practiced in the United States.

   Electromagnetic levitation for friction reduction is an important application of EM at the microlevel.

5. The special demands of catheter and endoscope manipulation are driving efforts to make practical shape-memory-alloy actuators in Japan. SMA techniques appear to be more advanced in Japan than in the United States.

REFERENCES

Akiyama, T., and K. Shono. 1993. "A New Step Motion of Polysilicon Microstructures." In Proceedings, IEEE Micro Electro Mechanical Systems Workshop. Pp. 272-277.

Ataka, M., A. Omodaka, and H. Fujita. 1993. "A Biomimetic Micro Motion System, A Ciliary Motion System." In Technical Digest, Transducers '93. Pp. 38-41.

Bleuler, H. 1992. "Proposals for Active Micro Levitation." In Technical Digest Volume, Third International Symposium on Micro Machine and Human Science. Pp. 129-136.

Fukuda, T., N. Mitsumoto, F. Arai, and H. Matsuura. 1992. "Design and Experiment of Micro Mobile Robot Using Electro-magnetic Actuator." In Tech. Digest Vol., Third International Symposium on Micro Machine and Human Science. Pp. 77-82.

Hirano, T., T. Furuhata, and H. Fujita. 1993. "Dry Released Nickel Micromotors and Their Friction Characteristics." In Tech. Digest, Transducers '93. Pp. 80-83.

Konishi, S., and H. Fujita. 1993. "A Conveyance System Using Air Flow Based on the Concept of Distributed Micro Motion Systems." In Tech. Digest, Transducers '93. Pp. 28-31.

Saeki, K., T. Koumura, T. Kaneko, and T. Hattori. 1992. "Aberration Reduction of Si Diaphragm Dynamic Focusing Mirror." In Tech. Digest Vol., Third International Symposium on Micro Machine and Human Science. Pp. 83-88.

Shikada, M., K. Sato, S. Tanaka, Y. Kawamura, and Y. Fujisaki. 1993. "Electrostatically-Actuated Gas Valve with Large Conductance." In Tech. Digest, Transducers '93. Pp. 94-97.

Tabata, O., R. Asahi, N. Fujitsuka, M. Kimura, and S. Sugiyama. 1993. "Electrostatic Driven Optical Chopper Using SOI Wafer." In Tech. Digest, Transducers '93. Pp. 124-127.

Teshigahara, A., M. Hisanaga, and T. Hattori. 1992. "Fabrication of a Shell-Body Microcar." In Tech. Digest Vol., Third International Symposium on Micro Machine and Human Science. Pp. 137-141.

Tsutsui, Y., N. Iwabuchi, T. Kabashima, M. Ikeda, and S. Yamashita. 1992. "Characteristics of Miniature Motor Using Thin-Film Magnet." In Tech. Digest Vol., IEEE 2nd International Workshop on Advanced Motion Control. Pp. 1-4.

Yasuda, T., I. Shimoyama, and H. Miura. 1993. "Microrobot Actuated by a Vibration Energy Field." In Tech. Digest, Transducers '93. Pp. 42-45.