Patent ID: 7799423

Claim:
A fabricated microstructure to adhere in shear to a contact surface, the fabricated microstructure comprising: a substrate; and a plurality of nano-fibers attached to the substrate, wherein the plurality of nano-fibers pack together into one or more clumps of mutually-supporting nano-fibers when not in contact with the contact surface, wherein the clumps break apart when the nano-fibers in the clumps come into contact with the contact surface; wherein the nano-fibers have an elasticity modulus E, an interfacial energy per unit length of contact w, a length L, a radius R, and are biased at an angle θ o relative to the substrate when the nano-fibers are not clumped together, wherein the length L of the nano-fibers is greater than 0.627θ o R 2 (E/w) 1/2 with θ o in radians, and wherein each nano-fiber includes a first end attached to the substrate and a free second end opposite the first end, and wherein a portion of the length of the nano-fibers contact the contact surface.