High aspect ratio micro actuation mechanism

A micro actuating structure with an out-of-plane erected body is designed, fabricated and tested. Different from the traditional micro actuators, which are located on substrate surface, this new actuation mechanism is capable of producing linear motion at a point far from substrate. This unique advantage brings the possibility of driving other 3-D structures for on or out-of-wafer applications like optical alignment or precise manipulation. The unique design of the planar structure fabricated by surface micromachining is making use of elastic polyimide joints to bring a movable large silicon plate in front of an other plate to form a parallel plate capacitor. The area of the capacitive plate is 430 microns/spl times/330 microns where the height of the structure is about 1 mm. A 2-D simplified mechanical model of the structure is build and used to estimate the mechanical behavior of the structure by using a commercial finite element analysis program.