Surface Nano-Structuring of NiTi alloy in Antibacterial Applications

The antibacterial performance of biomaterials and biomedical devices is attracting much attention from medical and materials researchers because bacterial infection is one of main causes of post-surgery complications and jeopardizes the health of patients. NiTi shape memory alloys have been widely used in biomedical devices due to their shape memory effect and superelasticity. In this work, an anodizing method is adopted to tailor the surface antibacterial properties of NiTi alloys. A hierarchical structure formed on the surface of this alloy is composed of continuous circular scallops with an average size of tens of micrometers. A continuous skeleton of several hundred nanometers consists of pits homogeneously distributed on the walls of these scallops. The exposed surface is composed of nanoparticles with an even and continuous distribution. Antibacterial tests show that the nano-structured surface can effectively prevent the proliferation and adhesion of bacteria on the surface.