Zero-Power Latching, Large-Stroke, High-Precision Linear Microactuator for Lightweight Structures in Space

This paper presents the successful demonstration of a latching-type, large-stroke, high-precision linear microactuator. The microactuator is capable of zero-power latching, or forcibly maintaining its position by using pre-stressed spring load. The actuator is driven by a combination of PZT actuator for slider thrust and electrostatic comb drive for slider grip. Incremental step size is precisely adjustable to tens of nanometer level by controlling PZT actuator voltage. Large stroke is obtained by repeating the operation sequence numerous times. Large stroke exceeding 600μm has been demonstrated. There is no conceivable limit to the stroke except for the length of the slider and external load.