Abstract: Hierarchical structures significantly influence the development of metal surface wettability. In this study, three kinds of hierarchical structures formed by the superimposition of different nanoscale (quasi-) periodic structures on micro-column arrays were fabricated on 304 stainless steel surfaces via picosecond laser irradiation. Scanning Electron Microscope (SEM) and Confocal Laser Scanning Microscope (CLSM) were used to characterize the created hierarchical structures. An optical contact angle meter was used to analyse the wetting performances. The results show that the surfaces of these fabricated samples have superhydrophobic properties and strong adhesion per-formances, which can be attributed to the formation of hierarchical structure that causes a reduction in the liquid-solid contact area and the change in the direction of surface tension. By controlling the dimensionof the nanotextures on the micro-column arrays, the hydrophobic property of 304 stainless steel surfaces can be greatly improved.

Key words: superhydrophobic, hierarchical structure, laser irradiation, bioinspiration, texture, adhesion, stainless steel