A Large-Displacement Out-of-Plane SOI Actuator for Applications in Confocal Microscopy

A silicon-on-insulator actuator has been designed for large DC deflections out of the plane of a wafer. The design employs deep reactive ion etching with a delay mask of two distinct silicon dioxide thicknesses to form silicon structures of two different heights. The low-high connection between beams of opposing thickness permits torsion-based actuation and consequent out-of-plane motions. A platter with pinhole aperture is demonstrated to deflect vertically using a combdrive for lateral force generation. The completed device may have applications in a design for confocal imaging on a chip, or may be used for active focusing in laser-fiber coupling. DC and AC responses of a vertical actuator were measured.