US Patent 9638176 Vortex generator using shape memory alloys

In one embodiment, the disclosed vortex generator may include a flap, a bearing configured to be mounted on a surface, an axle retained in the bearing, the flap attached to the axle such that the flap rotates relative to the bearing about the axle, and an actuator made of a shape memory alloy attached to the flap and to a support, the actuator shaped to receive the axle therethrough, such that a change in temperature of the actuator causes the actuator to rotate the flap relative to the bearing.