Jiyu Liu1 Guansong Wang1 Jichao Zhang1 Faze Chen1 Zhuji Jin1 Xin Liu1

1, Dalian University of Technology, Dalian, , China

Superhydrophobic surfaces with hydrophilic patterns have great application potential in various fields, such as microfluidic systems and water harvesting. However, many reported preparation methods involve complicated devices and/or masks, making fabrication of these patterned surfaces time-consuming and inefficient. Here, we propose a high-efficient, simple and maskless micro-plasma jet (MPJ) treatment method to prepare hydrophilic patterns like dots, lines and curves on superhydrophobic Al substrates. Contact angles, sliding angles, adhesive forces and droplet impact behavior of the created patterns are investigated and analyzed. The prepared “dot” patterns exhibit great water adhesion, while the “line” patterns show anisotropic adhesion. Additionally, MPJ treatment does not obviously change the surface structures, which makes it possible to achieve repeatable patterning on one substrate. Adhesion behavior of these patterns could be adjusted using MPJs with different diameters. MPJs with larger diameters are efficient for creation of patterns with high water adhesion, which can be potentially used for open channel lab-on-chip systems (e.g., continuous water transportation); while MPJs with smaller diameters are preferable in preparing patterns with low water adhesion for diverse applications in biomedical fields (e.g., loss-less liquid droplets mixing and cell screening).