Single step generation of microstructured hydrophobic Aluminium surface by ns laser

Abstract

Thin sheets of aluminium with thickness of 100 µm are micromachined with ultraviolet laser pulses of 30 ns, to create hydrophobic surface in a single step processing. The laser machined thin Al surface is free from cracks and thermal deformation. However, melting effect is well pronounced for the blind microholes structures irrespective of laser process parameters. The results show that the micropattern or blind microholes created by laser processing plays a major role rather than the chemical changes induced on the surface for improving the degree of hydrophobicity. Laser processed microholes provided hydrophobic surface behavior with maximum static contact angle of 148±3°. The static contact angle values are very consistent for, even bigger volume of water droplet such as 12µL.