Formation of picosecond laser-induced periodic surface structures on Steel and Titanium for knee arthroplasty prosthetic

Laser-induced periodic surface structures (LIPSS) have been studied extensively in recent decades due to their potential applications in various areas such as engineering, medical, optical, liquid transport and surface wetting, and friction and tribology. In this study, LIPSS is obtained on two prosthetic implants such as medical grade stainless steel and titanium in air and water using 1064 nm and 532 nm picosecond laser pulses. We obtained different surface morphologies depending on the environment and laser parameters. The surface morphology is analyzed by both Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). The analysis of images shows that obtained periodic structures are in Low Special Frequency LIPSS (LSFL) with periodicity of around 600 nm and 1100 nm for lasers with wavelengths 532 nm and 1064 nm respectively in air. The periodicity increased when the experiment is carried out in water medium for both wavelengths. The morphology and periodicity of the LIPSS pattern were strongly dependent on the fluence. Ongoing experiments on biofilm formation and bacteria attachment on the patterned surface will also be presented. In addition, surface wettability by sessile drop method with water and diiodomethane as testing liquid will be presented.