Micromachined actuators with braking mechanisms

New DRIE actuator systems have been developed which use a high-force, linear actuator to wrap a flexible brake band around the rigid brake shoe of a large-deflection, rotary actuator. The brake can hold the rotary actuator at any arbitrary location within its full range of travel. A third actuator may be used to engage a pair of locking pins in order to keep the brake motor extended in the event of a power failure. The 100 x increase in rotational stiffness after the brake is applied raises the fundamental resonant frequency by more than an order of magnitude, enabling precision optical adjustments over a large tuning range in the presence of external shock and vibration. (C) 2005 Published by Elsevier B.V.