"Innovative Actuators for Advanced Mechatronics and Instrumentation."

"Applications of actuators have increased in various fields. In industry, precise and high speed positioning is one of the most important technologies. Especially in the production of semiconductors and flat panel displays, dust-free transporting and precise positioning systems for wafers and thin glass plates are needed to avoid generation of dusts. In peripheral machines for computers like disc memories, small and thin linear actuators are necessary to satisfy the demand of reduction of thickness and weight of the products.Conventional motors driven by the electromagnetic force will play the most important roles. However, in some cases these conventional actuators seem to be difficult to satisfy the new and advanced demands in the near future. Therefore, seeking for new actuators has been activated.Our laboratory in the University of Tokyo has been enrolled to develop new actuators of various kinds in order to cope with severe demands of coming production systems and future automated machines. In our laboratory, a number of unique actuators and drive technologies were invented and realized. Among them, first, the following two actuators using piezoelectric materials, impact drive mechanism and surface acoustic wave motor, are introduced with applications. Impact drive method can move an object with a step of several nm to micrometers for a long distance by using rapid deformation of a piezoelectric element. The surface acoustic wave motor is a very thin ultrasonic motor with promising properties like large thrust, high velocity, and quick response. Then, as applications of electrostatic force, powerful electrostatic motor and new technologies of electrostatic transportation of particles, powder and droplets, sheets and films, and thin plates, are presented respectively with their principles and devices. And combining the technologies of electrostatic suspension without mechanical contact and electrostatic drives, super clean transportation devices for 300 mm and 400 mm silicon wafers and thin plates of glass for flat displays are introduced."