US Patent 7914912 Actively switchable nano-structured adhesive

Described herein is a microstructure having a substrate and a plurality of nano-fibers attached to the substrate. Each nano-fiber moves between the first and second states without an external mechanical load being applied to the nano-fibers. Each nano-fiber is configured to move between a first state and a second state in response to applied electricity, magnetism, chemical solution, heat, or light. Each nano-fiber is straight in the first state and curved in the second state, and when the nano-fibers are in the second state and in contact with a contact surface, the nano-fibers adhere to the contact surface.