Attachment/detachment electrostatic micro actuators for pan-tilt drive of a micro CCD camera

Newly developed linear electrostatic micro actuators employing an attachment/detachment mechanism and fabricated by a bulk silicon micromachining process are described. The moving part (slider) of these actuators is sandwiched between two glass plates whose surfaces have many electrodes (fixed electrodes), is attached to these fixed electrodes by turns up and down, and is actuated in the course of the linear motion. A feature of these actuators is that anti-friction bearings are not required and the influence of friction is reduced significantly. Several difficulties have been identified regarding attachment/detachment operation actuators. The accumulation of charge caused by contact between each stator and slider is one of the most difficult problems, and it can lead to complete actuator failure. The newly developed actuators have micro pyramid stoppers which prevent the accumulation of charge on both surfaces of the moving part. When a diving voltage of about 80 [V] is applied, the slider moves successfully with a /spl plusmn/1 [mm] stroke at a speed of 1.0 mm/sec under the condition of no load. The authors further apply these actuators to a micro pan-tilt mechanism for altering the vision angle of a micro CCD camera and experimentally confirm their practical utility.