writer：Peng Ge, Shuli Wang, Wendong Liu, Tieqiang Wang, Nianzuo Yu, Peihong Xue, Hongxu Chen, Huaizhong
keywords：none
source：期刊
specific source：Adv. Mater. Interfaces
Issue time：2017年

This paper reports the directional wetting behavior of water on a patterned

heterogeneous surface, which is integrated by two asymmetric nanostruc-

tures with different directions. The asymmetric nanostructures are Janus

silicon cylinder arrays (Si-CAs) modified by molecules with distinct surface

energies on two sides. Through a photolithography process, the two asym-

metric nanostructures are integrated in a single surface to form chessboard

patterns with different directions. When water is injected onto the patterned

surface, water droplets wet in a unidirectional manner, and the wetting direc-

tion is along resultant direction of the two wetting directions of water on

the two asymmetric patterns. This paper investigates the factors which may

influence the wetting behavior of water on the surface, experimental results

show that patterned asymmetric surfaces prepared from different chessboard

pattern size, Si-CAs with different diameters, and different morphology-

symmetric structures do not affect the wetting property, but the molecules

modified on two sides do. Larger surface energy difference between the modi-

fied molecules improves the ability of the surfaces induce water moving. It is

believed that the patterned asymmetric nanostructure arrays provide a new

strategy to modulate the wetting behavior of water, which will show poten-

tial applications in microfluidics and others involving unidirectional liquid

manipulation.