Title: In Situ Fully Light-Driven Switching of Superhydrophobic Adhesion

Author: Chao Li, Yuanyuan Zhang, Jie Ju, Futao Cheng, Mingjie Liu, Lei Jiang, Yanlei Yu*

Journal: Adv. Funct. Mater., 2012, 22(4), 760-763

Abstract:

An in situ fully light-driven switching of superhydrophobic adhesion is demonstrated based on simply spin-coating a hydrophobic azo-polymer on an optimized micro-nanopost arrayed silicon substrate. Furthermore, the detailed designing principles are discussed, which might shed light on efficient exploitation of superhydrophobic liquid/solid interfaces for smart microfluidic control.

Fulltext Link: https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.201101922

An in situ fully light-driven switching of superhydrophobic adhesion is demonstrated based on simply spin-coating a hydrophobic azo-polymer on an optimized micro-nanopost arrayed silicon substrate. With an alternating irradiation of UV and visible light, the azo-polymer coatings show a trans-cis photoisomerization, which leads to a reversible change both in contact angles and the adhesion reaction. This kind of real-time controllable microdroplet’s adhesion might inspire and facilitate the designs and applications in novel microfluidic devices, e.g., remote-controlled valve, sensor, mechanical hand, microreactor, and so on. Moreover, the design principles disclosed in this work shall be a guidepost for the following researches on smart solid/liquid interfaces with on-off switching of superhydrophobic adhesion.