Fabrication of Pre-Assembled Polysilicon Micromechanical Structures.

This memorandum describes the in-place fabrication of linear and rotary polysilicon micromechanical structures, using surface micromachining techniques. Turbines with gear and blade rotors as small as 125 micrometers in diameter and 4.5 micrometers in thickness were fabricated on 20 micrometer diameter shafts. A clearance as tight as 1.2 micrometers was achieved between the gear and the shaft. Gear-trains with two or three sequentially aligned gears were successfully meshed. A sub-millimeter pair of tongs with a 400 micrometers range of motion at the jaws was fabricated. This structure incorporates a single linear sliding joint and two rotary joints, demonstrating linear to rotary motion conversion.