LIPSS: A promising strategy for the generation of effective bacteria-repellent surfaces

Bacterial adhesion and subsequent biofilm formation is a significant problem in the food industry and healthcare environments due to the large number of diseases they cause. To address this issue, research is focused on the development of antibacterial surfaces. This article details the generation of a type of nanostructure called Laser-Induced Periodic Surface Structures (LIPSS) on ferritic stainless steel as potential solution. LIPSS, generated with a 343 nm laser wavelength and with a 260 nm spatial period, have been shown to significantly reduce bacterial adherence: up to 43 % for Staphylococcus aureus and 70 % for Salmonella spp. The topography of the nanostructured surface with LIPSS hinders bacterial adhesion by reducing the contact area between bacteria and surface. Furthermore, the physical properties of LIPSS, such as surface potential and dielectric constants, determined via Atomic Force Microscopy and ellipsometry, show that bacteria are more attracted to the ridges than to the valleys of the LIPSS, favoring the adhesion on these regions. X-ray energy-dispersive spectrometry measurements confirm these findings. In conclusion, LIPSS effectively inhibit bacterial adhesion by altering surface topography and physical properties. These results highlight the potential of LIPSS as a strategy for designing antibacterial surfaces to mitigate biofilm formation in various applications.