Development of electromagnetic linear actuators for micro robots

For micro robotic applications, piezoelectric actuators are widely used, whereas electromagnetic actuators are not favored because of the complex structures and difficult fabrication. On the other hand, electromagnetic actuators have many merits that are suitable for robotic applications, such as relatively large displacement or stroke and no need of high voltage power supply. With the recent fast development of micro precision machining techniques, the fabrication of complex structures is no longer a problem. This paper presents our recent study of developing electromagnetic actuators for micro robotic applications, including a comparison between piezoelectric and electromagnetic actuators, design of two types of electromagnetic actuators, and fabrication and testing of a moving magnet tubular linear actuator.