Super Hydrophilic Surface Fabricated on Alumina Ceramic by Ultrafast Laser Microprocessing

Super-hydrophilic alumina ceramic materials have wide application prospects in various fields and have drawn broad research interest. The failure of the hydrophilic surface is currently the main problem that limits its practical application. We have developed a simple method to directly fabricate super-hydrophilic surface on alumina ceramic by ultrafast laser micromachining. The super-hydrophilic surface fabricated on alumina ceramics by femtosecond laser can maintain the super-hydrophilic property at 0° for 48 hours. The contact angle of 54.9°still have hydrophilic properties after 240 hours. This is due to the increased surface roughness and the change of chemical composition on the ceramic surface treated by ultrafast laser. The groove surface with V-shaped profile enlarging the contact angle hysteresis and with capillary forces improving the spreading wetting of liquid along the grooves reduce the contact angle directly. The increase in the polar groups of surfaces and the polar component of the surface energy after laser treatment also improve the behavior of wetting and adhesion. It is noted that surface morphology plays a leading role in enhancing the wettability. This research provides guidelines for designing the surface micro-structuring based on desired geometric features and properties of alumina ceramic materials.