Abstract: A comb-drive actuator includes a stationary comb structure having stationary comb fingers interdigiated with comb fingers of a mobile comb structure. The comb fingers include a p-type layer and an n-type layer forming a diode junction in each finger. The diode junctions of either the stationary comb fingers or the mobile comb finger are reversed biased, while at least one layer of the other set of comb fingers is grounded. This creates an attractive electric field between the sets of fingers, causing the mobile comb structure to move. The mobile comb structure of the actuator can be aligned along the rotational axis of a movable element and attached at one end to the movable element and at the other end to a flexure. The comb fingers can also be shaped to provide multi-gap and/or variable gap configurations between the stationary and mobile comb structures.