Closed loop controlled, large throw, magnetic linear microactuator with 1000 /spl mu/m structural height

Abstract

A linear magnetic actuator has been developed and fabricated for use in a closed loop control system. The actuator is an assembled device with a structure height of 1000 /spl mu/m and output force in the 100 milliNewton range. The actuator produces a large inductance change as it is displaced. The position dependent inductance is measured by control circuitry and used for micro positioning. The closed loop control system is capable of using inductance or capacitive feedback to produce stable position control. The control circuitry can produce submicron positional accuracy while minimizing the circuit cost and complexity. The control circuitry has been tested with the actuator and closed loop control has been obtained.