SURFACE MICROMACHINED MICROENGINE

The design, fabrication, and preliminary testing of a polysilicon micr oengine are presented. In this early work, electrostatic comb-drive ac tuation is used to demonstrate the microengine. However, the basic gea r/link element of the microengine can be driven by any suitably forcef ul linear actuators. This device has direct application as a drive and power source for micromachined mechanisms such as optical switches, e lectrical switches, micropositioners, or any other micro-sized device requiring mechanical power. This is the first device of its kind that is directly linked to an output gear and converts linear motion from c omb-drive actuators to rotational motion. The microengine provides out put in the form of a continuously rotating output gear (approximate to 50 mu m in diameter) that is capable of delivering torque to a microm echanism. The microengine can be operated at varying speeds and its mo tion can be reversed. Processing considerations address the eliminatio n of natural interferences that arise when conformally deposited polys ilicon films form the links, joints, and gears that comprise the micro engine. The resultant device is completely batch fabricated without th e need for piece-part assembly.