INTEGRATED MULTILAYER HIGH-ASPECT-RATIO MILLIACTUATORS

We report here an integrated multilayer high aspect ratio process, and mm-sized electromechanical actuator structures fabricated by this pro cess. The high aspect ratio microfabrication process allows the genera tion of structures an order of magnitude larger than conventional stru ctures in all three dimensions, while still retaining the minimum in-p lane features. We will describe a detailed example of a 1-mm-sized mic rofabricated actuator with a linearized output capability of 0.2 mN wh en driven at 60 V. In addition to the high aspect ratio microfabricati on process, the high force output is achieved through an area-efficien t design and a large-signal linearization scheme. The area-efficient d esign allows full utilization of the chip area for energy conversion. The large-signal linearization scheme permits a linearized force outpu t with driving voltages as large as the biasing voltage. This increase d output force enables the batch-fabricated microactuators to be used in many new, practical applications in which the microactuators are re quired to move an additional load as well as their own mass. Other str uctures made possible by this process are fully-integrated wobble micr omotors with notched pin-joints for extended high aspect ratio gaps be tween rotors, stators and axles.