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

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.