US 6000280 A A comb-type actuator for movable
microelectromechanical structures includes first and second
asymmetric sets of interdigitated fingers. Asymmetry is obtained
by fabricating on set of fingers to have a greater height than
the other set, or by providing electrically insulating segments
in one set. Application of a voltage across the sets produces an
asymmetric field between them and produces relative motion. 1. A
comb-type actuator for microelectromechanical structures,
comprising: a first set of fingers mounted on a substrate; a
second set of fingers mounted on a movable structure for
relative motion with respect to said first set of fingers, the
fingers of said first set being interdigitated with the fingers
of said second set, said first and said second sets of fingers
being asymmetrical; and a voltage source connected to produce an
electric field between said first and said second sets of
fingers to thereby produce a predetermined relative motion
between said sets of fingers. 2. The actuator of