Biased rotatable combdrive devices and methods

Abstract

Rotating devices including actuators and position sensors that employ combdrives are described. One design of a combdrive fabricated from a single layer is provided such that, in a nominal state, the two sets of comb fingers are substantially interdigitated according to a predetermined engagement. A rotating element may be attached to a rotatable flexure disposed along an axis and coupled to the comb fingers along with a biasing element attached to the rotating element to cause the comb fingers along with the rotating element to undergo a controlled angular displacement from the initial engagement and in response to feedback from sensing the position of the movable or rotating element. A voltage may be applied between comb fingers to cause the rotating element to undergo further rotation about the axis in a predetermined manner. Alternatively, a time-vary biasing force may be exerted on the rotating element, causing the first comb fingers along with the rotating element to undergo further rotation about the axis in a predetermined manner. The combdriven device can serve as both rotating actuators and position sensor. By arranging two such combdrives in a gimbaled structure bi-axial rotating actuators and position sensors may be constructed. The combdrive devices of the present invention can be employed in a broad range of applications, including biomedical devices, optical devices for tracking and display, telecommunication devices such as fiber-optic switches, inertial sensors, and magnetic disk drives.