Gecko-inspired adhesion controlled by light

Abstract

A team of German researchers have created an adhesive pad inspired by the sticky feet of geckos that unsticks from objects when triggered by ultraviolet light. The pad could lead to robotic fingers controlled by light that can pick up and release delicate objects. Geckos can scurry up and down walls thanks to about half a million fibers called seta on each of their feet. Each setae is divided into hundreds of spatula-like nanostructures that individually grip a surface through weak van der Waals interactions. Collectively, these millions of interactions lead to strong adhesion. In the new work, Emre Kizilkan of Kiel University and his colleagues used previously developed surfaces with mushroom-shaped polydimethylsiloxane microstructures to produce geckolike adhesion. But for easy manipulation, they desired a system that could attach and detach its adhesive hold at will. “We wanted to control the adhesion by light,” Kizilkan says. To do so, the