Fabrication of durable haemophobic surfaces on cast acrylic sheets using UV laser micromachining

Abstract

A low-cost, high-speed micro-scale patterning procedure for generation of durable blood-repellent patterns on polymers using continuous wave (CW) ultraviolet (UV) laser with optical lens arrangement is demonstrated in this work. A laser engraver which can generate patterned structures in the range of 1-300 µm employing a 5 W, 445 nm CW UV laser with collimating lens arrangement was developed for this purpose. Subsequently, cell cast high impact acrylic sheets of 5 cm × 5 cm size were patterned to generate fishbone architecture like microstructures with central structure footprint 71.3 µm, peripheral structure footprint 29.8 µm and peripheral structure spacing of 77.8 µm. The patterned acrylic was evaluated for hydrophobicity and human blood-repellent nature using a contact angle goniometer. Hardness tests for checking durability of the patterned surfaces for various biomedical applications were conducted using a hardness tester. The tested Vickers hardness of the acrylic patterned sample was 17.41 HV which indicates durability of the fabricated patterns. Maximum static contact angle of 142.3°and minimum roll-off angle of 11.7°observed for blood on patterned acrylic confirm the haemophobic nature of the fabricated surfaces.