Self-assembled anodization of NiTi alloys for biomedical applications

Nearly equiatomic nickel-titanium (NiTi) alloys are used in many biomedical applications due to their favorable properties, but in some cases, the surface properties such as corrosion resistance and biological characteristics may be inadequate, especially for clinical applications. Electrochemical self-assembly is an emerging surface modification method for valve metals and their alloys and the ordered oxide nanostructures produced by this method not only increase the corrosion resistance, but also regulate the cell behavior. Herein, recent advances pertaining to self-assembled anodization of NiTi alloys and biomedical applications are described. In particular, the influence of the preparation parameters on the morphology, microstructure, composition, corrosion behavior, Ni ion release, and biological response of self-assembled Ni–Ti–O nanotubes and nanopores are comprehensively analyzed and discussed.