Femtosecond laser patterned alumina ceramics surface towards enhanced superhydrophobic performance

Superhydrophobic surfaces are used in fields such as self-cleaning, anti-corrosion and anti-rust, and electromagnetic shielding because they are not wetted by water droplets. We manipulated the scanning spacing and scanning times of the femtosecond laser to control the surface morphology of alumina ceramics, resulting in the creation of two microstructures: micropillars and microhills. Subsequent heat treatment in an oven at 100 °C for 12 hours formed a superhydrophobic surface without additional chemical modification, with a contact angle as high as 171.706°. Experimental results show that the superhydrophobicity of the alumina ceramic surface is due to the micro-nano structure of the ceramic surface under specific laser parameters and the hydroxylation of the alumina ceramic itself combined with organic compounds in the air. In addition, the ceramic still has excellent superhydrophobic properties up to 155° after being left in the air for 35 days and abraded by 800-grit sandpaper for 1m under a pressure of 2.2kpa. Our work uses a new environmentally friendly method to make alumina ceramic surfaces both wear-resistant and superhydrophobic.