Enhancing wettability of sapphire (Al2O3) substrate through laser surface texturing

Abstract

Sapphire (Al2O3) has emerged as an incredibly versatile ceramic material, attracting significant interest across various fields due to its superior properties. The potential to control its wettability offers opportunities for enhancing the functionalities of sapphire-based devices. This study focuses on achieving superhydrophilic surfaces on sapphire substrates using a 355 nm nanosecond laser. The effects of the Laser Surface Texturing (LST) parameters on the morphology and wettability of the samples were examined through a Taguchi L16 experimental design. The results showed that the repetition rate and scanning speed influenced the Contact Angle (CA) and Surface Roughness (Ra) of the laser-textured sapphire. Lower repetition rates and higher scanning speeds resulted in rougher surfaces and smaller contact angles. The minimum CA of 4.5° was obtained at a repetition rate of 50 kHz and a scanning speed of 1100 mm/s. The study highlights the importance of controlling processing parameters to achieve desired wetting properties for superhydrophilic surfaces. The findings of this research provide insights into the application of LST for achieving superhydrophilic surfaces on sapphire substrates.