Laser Micro-texturing of Titanium Surfaces for Enhanced Hydrophobicity for Biomedical Applications
摘要
This research work highlights the techniques to improve the hydrophobicity of the titanium alloy (Ti–6Al–4V) using laser surface texturing. Different micro-textures, namely, hatched, windowpane, cross-hatched, dash-hatched, and striped, were fabricated with different offset distances on the titanium alloy surface to improve the wettability. The process parameters considered in this are the scanning speed (1000 and 2000 mm/sec) and power (16 and 18 W) with a constant pulse frequency of 10 kHz. Furthermore, the surface morphological features on the fabricated textures were analyzed by using an optical microscope and a digital USB microscope. The contact angle was significantly increased after laser micro-texturing. Among all the texture types, windowpane and cross-hatched texture have attained the maximum contact angle, which is categorized as hydrophobic in nature and is nearly doubled as compared to the contact angle of as-received titanium alloy. The results of the wettability test demonstrated that the contact angle increases following low-temperature annealing. From the overall wettability test results, the cross-hatched texture formed with the laser texturing parameters of 16 W of power, 1000 and 2000 mm/sec of scanning speed, and 10 kHz of pulse frequency and an offset distance of 0.3 mm displayed extremely hydrophobic behavior with a 133° contact angle, which is considerably higher than the as-received surface contact angle of 74.6°. Based on the values of the measured contact angles, it is shown that the surfaces can be tailored to improve the hydrophobicity for suited medical assistive devices and bio-implants.