Studies of micro actuators in Japan

Various kinds of driving principles are proposed for micro actuators. Electrostatic, superconducting, piezoelectric, and shape-memory alloy actuators are studied, with emphasis on work done in Japan. Electrostatic actuators, a superconducting actuator, an actuator which simulates muscles, a microfluid system with piezoelectric actuators, and a cell fusion system based on a fluid integration circuit are described. Microactuators and the micro machines driven by them are expected to have wide varieties of applications in medical, bioengineering, optics, information machinery, and robotics fields. It is shown that before a practical microsystem is distributed, however, there are still difficulties such as micro sources, packaging, interfacing, reliability, and control of many autonomous systems