NASA Langley has developed a self-latching piezocomposite actuator with power-off, set-and-hold capability. If integrated into an aerodynamic control surface or engine inlet, deflections could be made in flight and set and maintained (latched) without a constant power draw.
The control device leverages the shape memory behavior (specifically, the remnant stress-strain behavior) to create a morphing actuator that changes and holds the new shape with no applied control signal.