Microfabricated dry adhesive displaying frictional adhesion

Abstract

Gecko adhesion has inspired many engineered adhesives. Many of these gecko-like synthetic adhesives (GSAs) only replicate the fibrillar aspect of gecko adhesion. We present here a new GSA, MicroWedges, which demonstrates the gecko properties of dynamic adhesion, frictional adhesion, and massive reusability. Mi-croWedge fibers individually attach and detach during shear sliding, maintaining shear and normal adhesion. MicroWedges also exhibit the gecko-like property of frictional adhesion. Increasing the shear load on a patch of MicroWedges increases the normal adhesion. MicroWedges also demonstrate the gecko-like properties of anisotropy and high μ’. MicroWedges are fabricated in PDMS from a reusable mold formed from SU-8. The SU-8 is exposed in a dual-side, dual-angle lithography process on transparent wafers.