Device having controllable adhesion

摘要

A combination includes a first device and a second device, wherein both devices comprise at least one surface and the surface of the first device comprises at least one recess. At least one contact surface is formed when the surface of the first device attaches to the surface of the second device. By applying external pressure, the adhesion force between the two devices can be switched back and forth between at least two states.

主权项

1. A combination, comprising:
a first and a second device, both devices each having at least one surface, the surface of the first device having at least one recess comprising an axially symmetrical recess; and the surface of the first device being contacted to the surface of the second device by adhesion forces, so that at least one contact area is formed which comprises at least one common contact area wherein the contact area in at least one recess has at least one region which has not formed any common contact area, wherein the combination satisfies the following equation:δ02⁢E*bw0>2⁢π,where δ0 is a maximum depth of the at least one recess,b is an effective radius of the at least one recess,w0 is a reduction in potential energy per unit of the common contact area,
w0=γ1+γ2−γ12 where γ1 is a surface energy of the first device and γ2 is a surface energy of the second device and γ12 is an interface energy of the two devices on contact, andE* is a combined modulus of the two devices according to1E*=1-v12E1+1-v22E2where E1 and E2 are moduli of elasticity of the first and second device, respectively, and v1 and v2 are Poisson numbers of the two devices.