Wettability Control of Sapphire by Surface Texturing in Combination with Femtosecond Laser Irradiation and Chemical Etching

Surface texturing has been recently utilized in interface science to modify the liquid wettability of solid surfaces. In this paper, the authors present a simple method to control the surface wettability properties of sapphire by surface texturing in combination with femtosecond laser irradiation and chemical etching. Four type surface microstructures were fabricated by controlling the pulse overlap rate between the laser beam tracks and by chemical etching. The original hydrophobic surface can be transformed into superhydrophobic surface after femtosecond laser irradiation. The femtosecond laser firstly made the sapphire surface phase transformation, then combining with chemical etching, the hydrophilic surface can be obtained. It is found that surface texturing in combination with ultrafast laser irradiation and chemical etching is an effective way to manipulate surface microstructure and liquid wettability.