MIT Department of Electrical Engineering & Computer Science

April 11, 1995
3:30 Reception, 4:00 Lecture
Room 34-101, 50 Vassar Street

Title: Design, Fabrication, and Application of Magnetic Microactuators

Mark Allen
Georgia Institute of Technology
Atlanta, Georgia

Magnetic microactuators offer an attractive alternative for the realization of actuation in microsystems. For example, although electrostatic and piezoelectric actuation are widely used in microsystems, magnetic microactuators can operate in environments where high driving voltages are unacceptable, such as conducting fluids and dust-filled or hazardous environments. In addition, the low-voltage, high-current nature of magnetic drive is well matched to many larger systems such as automotive systems. In this talk, processes based on polyimide molds and electroplating for realizing magnetic microactuators with integrated driving coils will be discussed. The processes are inexpensive and use only conventional clean room equipment and commercially available materials. Due to thickness and material limitations in photolithographic-based fabrication of magnetic microactuators, it is often found that the magnetic reluctance of the core of the actuator cannot be neglected, necessitating the development of specialized design criteria for realizing maximum force from these reluctance-limited devices. Design rules for these devices will be presented. The design and fabrication of these devices will be illustrated by the use of four examples: a micromachined inductor for power electronics applications; a fully integrated micromachined magnetic actuator which can be used as a prototype magnetic relay device; a functional magnetic micromotor with integrated coil windings; and a magnetic particle separator which has been designed for biological particle separation applications.