Preparation of super-hydrophobic textures by using nanosecond pulsed laser

Over period of time human beings are imitating various features from nature to improve performance of their machines and operations. This work attempts to imitate features on a lotus leaf, which has super-hydrophobic properties due to presence of pillar like micro structures on its surface. Paper demonstrates fabrication of super-hydrophobic surfaces on stainless steel 316 using nanosecond pulse laser. Compared with ultrafast laser system used for such texturing, infrared nanosecond laser offers a lower cost and more robust system combined with potentially much higher processing rate. The wettability has been improved of textured surface developed from hydrophobicity to super-hydrophobicity over time when exposed to ambient conditions. The change in wettability property is attributed to partial deoxidization of surface induced during laser texturing. With the proposed method textures exhibiting contact angle up to 157 degrees with hysteresis of around 3-4 degrees have been achieved. Interestingly, the super-hydrophobic surfaces have self-cleaning ability and have potential for chemical sensing and bio-medical applications. (C) 2020 Elsevier Ltd. All rights reserved.