Control and Patterning of Various Hydrophobic Surfaces: In-situ Modification Realized by Flexible Atmospheric Plasma Stamp Technique

Wettability plays a vital role in fundamental researches and practical applications. Wettability control and patterning have been widely studied in various fields. Although researches have grown rapidly, the methods are still restricted by limitations including complicated processes, high equipment requirements and shortage of methods to treat complex surfaces. Here we report a simple, low cost, array-based wettability control and patterning method via in-situ modification by flexible plasma stamp. Wettability control and patterning on surfaces of superhydrophobic aluminum, superhydrophobic PDMS and silicon, even plant leaf and fruit are achieved. The relationships between the wettability and the treatment time are investigated. We elucidate that the wetting states can also be reversible. The surface modification mechanism of in-situ plasma treatment is further investigated. Utilizing the step by step treatment, gradient and arbitrary wettability patterning on surfaces have been obtained. Notably, the patterned wettability on the inner surface of a tube has been realized, which has never been reported. Finally, in-situ wettability patterning is applied to achieve microfluidics channels on the inner surface of superhydrophobic tube. This work will bring new insights into the study of wetting field and stimulate more applications on wettability control and patterning.