Stretchable, Adhesion-Tunable Dry Adhesive by Surface Wrinkling

We introduce a simple yet robust method of fabricating a stretchable, adhesion-tunable dry adhesive by combining replica molding and surface wrinkling. By utilizing a thin, wrinkled polydimethyl siloxane (PDMS) sheet with a thickness of 1 min with built-in micropillars, active, dynamic control of normal and shear adhesion was achieved. Relatively strong normal (similar to 10.8 N/cm(2)) and shear adhesion (similar to 14.7 N/cm(2)) forces could be obtained for a fully extended (strained) PDMS sheet (prestrain of similar to 3%), whereas the forces could be rapidly reduced to nearly zero once the prestrain was released (prestrain of similar to 0.5%). Moreover, durability tests demonstrated that the adhesion strength in both the normal and shear directions was maintained over more than 100 cycles of attachment and detachment.