Experimental and computational study on laser-induced microchannel topography to tailor the wettability of titanium surfaces for biomedical applications

Fibre lasers are preferred for micromachining due to their superior beam quality and minimal maintenance. This study presents the fabrication of microchannels on a titanium surface using a fibre laser. Taguchi's design of experiments was employed to evaluate the influence of laser parameters on channel geometry. Laser power was found to be the most significant factor affecting channel width and depth, followed by scan speed and the number of passes. Numerical simulations in COMSOL predicted channel geometry with an error of 2–24% compared to experimental results. Surface analysis revealed microcracks, pores, a recast layer, and oxidation due to localized heating. Wettability studies showed a notable change in surface behaviour after laser texturing. The untextured titanium exhibited a contact angle of ∼73°, which reduced to 33° immediately after processing, indicating hydrophilicity due to oxide formation. After 1 month of exposure to ambient air, the contact angle increased to 129°, confirming a transition to hydrophobicity caused by carbonaceous layer deposition. The results demonstrate that laser-fabricated microchannels effectively alter the surface topography and wettability, making titanium surfaces promising for biomedical applications that require tailored surface interactions.