Potential tribological and antibacterial benefits of pulsed laser-deposited zirconia thin film on Ti6Al4V bio-alloy

The experimental results depicting the advantages of pulsed laser deposition of zirconia thin film on Ti6Al4V bio-alloy at room temperature and at 200 °C substrate temperature in improving its biofunctionality are presented. A comparison of the change in surface roughness, wettability, surface free energy, tribological and antibacterial properties of uncoated and zirconia-coated Ti6Al4V samples clearly revealed the advantage, especially when deposition was carried out at higher substrate temperature. The coated samples exhibited lower coefficient of friction and a notable reduction in the wear rate. The in vitro bacterial retention test showed a clear inhibition in growth of Staphylococcus aureus and Klebsiella pneumonia bacteria on the surface of the coated samples indicating the possibility of prevention of biofilm formation. Superior antibacterial properties of the coated surface were also revealed by fluorescence microscopy where an increased percentage of bacteria was found to be decimated. Thus pulsed laser deposition of zirconia thin film coating on Ti6Al4V improves both, its tribological and antibacterial properties simultaneously. This, in return, is expected to increase the durability of artificial implant in the human body.