Special Issue on Innovative Actuators

Actuators are defined as transducers that convert electrical energy to mechanical movement. Similar to sensors and control systems, actuators are essential devices in various industrial applications, such as robotics, precise positioning systems, and automobiles. The performance required of each actuator depends on its practical application, and the actuators may determine the total performance of the systems. Various types of actuators have been proposed, not only for high efficiency, torque, and power output but also for flexibility, miniaturization, and drivability under extreme conditions. In the case of fluid-based actuators, the control of the working gas or liquid becomes an indispensable technology. The creation of a device with a simple structure yet multiple degrees of freedom would be quite worthy of research. Such an actuator would lead to future applications, which would in turn enable humanlike movements in robots, ultra-precise positioning systems under extreme high (or low) temperature conditions, or MEMS devices that operate in the human body. This special issue, entitled Innovative Actuators, is a collection of seventeen papers related to these considerations. In addition to electromagnetic motors, various types of actuators, such as piezoelectric, electrostatic, and pneumatic motors. Although the primary focus is on new driving principles, the fabrication process for micro devices and the control system are also involved. These proposals are attractive and sure to stimulate further innovative research. I hope you enjoy this special issue, but beyond that I hope that the papers in it contribute to your future research and innovative breakthroughs. On a final note, I wish to express my appreciation to the authors, reviewers, publisher (Mr. S. Wakai), and two editors (Assoc. Prof. T. Kanda and Assoc. Prof. K. Takemura) for their devoted work on this special issue, Innovative Actuators.Takeshi Morita June 23, 2016