Effects of periodic surface structures induced by femtosecond laser irradiation on the antibacterial properties of Zr-based amorphous material

In this essay, a femtosecond laser is used to create various structures on the surface of Zr-based amorphous material. Through the raster scan mode, under different laser energy densities, LIPSS (Laser-induced periodic surface structures), SWPSS (Super-wavelength periodic surface structure) and microporous structures were obtained in the experiment. Various surface properties of the micro-nano structures were tested. Experimental results illuminate that laser energy fluence is the key to determining the formation of nano- and microscale structures. The laser treatment greatly improves the surface roughness of the sample. The laser texture converts the originally hydrophilic specimen surface into a hydrophobic surface, which greatly reduces the material's surface energy. We found that all the formed surface structures can reduce the adhesion of Escherichia coli and Staphylococcus aureus. In detail, the adhesion rate of bacteria on the surface of SWPSS is the lowest. This article comprehensively discusses the influence mechanism of nano- and microscale structures on bacterial adhesion from four aspects: surface roughness, hydrophobicity, surface energy, and surface morphology. The study manifest that the period and amplitude of the nano- and microscale structures are the keys to bacterial adhesion. In addition, experiments have shown that nano- and microscale structures can effectively improve the corrosion resistance of zirconium-based bulk metallic glass.