SURFACE-MICROMACHINED GEAR TRAINS DRIVEN BY AN ON-CHIP ELECTROSTATIC MICROENGINE

Test results for a polysilicon, surface-micromachined, electrostatical ly-actuated microengine driving multiple gears are presented. The micr oengine provides output in the form of a continuously rotating output gear (50 mu m in diameter) that is capable of delivering torque to add itional geared mechanisms. The microengine can be operated at varying speeds and its motion can be reversed. A rotational speed of up to 200 000 r/min while driving multiple gears has been obtained. Drive of a 1 600 mu m diameter optical shutter has also been demonstrated. The resu ltant microengine and gear train, produced by polysilicon surface-micr omachining techniques, are completely batch-fabricated without the nee d for piece-part assembly.