Proceedings of the
9th International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2022)
15 – 18 November 2022, Singapore

Laser Micro/nano Surface Texturing of SS316L for Superhydrophobicity

Xincai Wang1,a and Yin Chi Wan1

1Singapore Institute of Manufacturing Technology (SIMTech), A*STAR, 2 Fusionopolis Way, #08-04, Innovis, Singapore 138634


Suitable modification of material's surface wettability has been attracting much attention in both scientific research and industry development due to its importance for various applications, which include lab-on-a-chip devices in microfluidics, self/easy cleaning, adhesion mitigation and biomedical application. Surface morphology plays a key role to determine the wettability of a solid surface. Various techniques have been used for surface texturing to create the desired surface morphologies. Laser micro- and nano-processing is one of the main techniques. Ultrafast lasers are increasingly used as a tool for surface texturing. Laser ablation by ultra-short pulses in the pico- or femto-second range results in well controlled superimposed micro- and nano-scaled surface textures. The microscale of the texture is mainly determined by the dimensions of the laser spot, whereas the superimposed nano-structure is the result of the so-called laser induced "self organizing nanostructuring". By controlling this micro-nano surface texture, it is possible to create two-scale hierarchical surface structures with the desired properties.

In the paper, 1.06 µm ps laser is employed to fabricate micro/nano surface textures on SS316L substrate. The effects of different laser parameters including laser fluence, rep rate, scanning speed, pass number, focal position, etc on the topography, feature profile, feature dimensions of the induced surface textures have been studied. The optimum laser parameters have been identified that the uniform-distributed 2 scale micro-nano hierarchical surface patterns are fabricated on the SS316L substrates. The fabricated 2-scale micro/nano hierarchical textured SS316L sample shows stable superhydrophobic property with a water contact angle (WCA) of more than 150 degree. Also, it is demonstrated that the laser textured SS316L surface has liquid repellent property to the liquids including coke, milo, dark soya sauce, and honey liquid. The mechanism involved in the process is discussed in terms of surface morphology and surface chemistry.

Keywords: Laser surface texturing, SS316L, hierarchical micro/nano structure, superhydrophobicity, self/easy cleaning

PDF Download