Micro/Nano-Structuring of Medical Stainless Steel using Femtosecond Laser Pulses

The medical stainless steel (SUS 304) surface is irradiated by femtosecond laser pulses with linear or circular polarization to form nanostructure-covered conical microstructures. The mean spacing of the conical microstructures and the type of the nanostructure can be controlled by the laser-processing parameters. The liquid test (water and normal-saline solution) demonstrates that the process provides a fast single-step structuring method to generate hydrophobic-enhanced metal parts. The biocompatibility test demonstrated that the femtosecond laser micro/nano- structuring surfaces have excellent biocompatibility properties compared to an untreated surface.