A hierarchical gecko-inspired switchable adhesive

Abstract

The gecko, as well as other insects and lizards, have a very clever mechanism for reversibly adhering to just about any surface. An integrated multi-scale system enables geckos to run up, down and across vertical or inverted surfaces. Here we report the fabrication of a switchable on/off adhesive. Inspired by the gecko, a hierarchical system composed of aligned vertical polymeric nanorods coating ferromagnetic nickel platforms was fabricated. When subjected to a magnetic field, the nickel platforms undergo a reversible conformational change, reducing the available contact area, and reducing adhesion by 40 fold. Development of such adhesives will lead to a new paradigm in latching systems, and will enable microrobots to climb just about anything, allowing them to enter environments inhospitable to man.