Ultrafast Laser-Induced Surface Structuring of Anti-Fouling Steel Surfaces for Biomedical Applications

Abstract

Metallic surfaces are increasingly used in medical applications due to their favorable material properties such as high strength and biocompatibility. In medical applications anti-fouling properties are an important requirement especially for implants and medical devices which come into contact with different types of fluid streams. These should be anti-fouling in order to prevent contamination and corrosion. Laser processing methods such as ultrafast laser processing is a one-step and scalable process for surface texturing. This process can be used to produce well-defined surface nano- and microscale superficial textures such as Laser-induced Periodic Surface Structures (LIPSS) which can enhance the anti-fouling capability of the surface. In this study, micro and nano scaled LIPSS structures are manufactured on a biocompatible grade stainless steel 316L substrate using an ultrafast (< 370 fs) and low power (< 4 W) laser system. With an aim to optimize the anti-fouling properties, laser process parameters such as pulse energy, pulse repetition rate and beam scanning speed were varied to produce microstructures on the stainless-steel surface of varying dimensions. Surface roughness was analyzed using a laser surface profilometer and changes in the hydrophobicity were examined using water contact angle goniometry.