Dayeong Kim , Jungmok Seo , Sera Shin , Soonil Lee , Kilsoo Lee , Hyeonjin Cho , Wooyoung Shim , Han-Bo-Ram Lee , and Taeyoon Lee
Chem.Mater. June 30, 2015
http://dx.doi.org/10.1021/acs.chemmater.5b01038
Abstract
Adhesion control of various liquid droplets on a liquid-repellent surface is a fundamental technique in novel open-channel microfluidic system. Herein, we demonstrate reversible liquid droplet adhesion switching on superamphipho-bic Pd-decorated Ag dendrites (Pd/Ag dendrites). Although adhesion between liquids and the superamphiphobic surfaces was extermely low under air ambient, high adhesion was instantly achieved by exposure of the dendrites to 8% hydrogen gas. Transition from low to high adhesion and the reverse case was successfully repeated over 10 times by switching from atmospheric ambient to 8% hydrogen gas. This is the first technique that allows real-time reversible adhesion change with various liquid droplets to a surface using gas-induced structure changes, and can potentially be used to realize various functions for droplet-based microfluidics.
