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Biomedical implant failure arises mainly from the degradation caused by tribological processes occurring in the corrosive environment the human body represents, known as tribocorrosion. The material loss and metal ion release resulting from tribocorrosion processes compromise the biocompatibility of metallic implants. The deposition of protective coatings on metallic substrates is a promising solution to overcome this problem. Pure titanium (Ti-cp) is widely used as an implant material due to its excellent corrosion resistance and high biocompatibility. However, its mechanical properties must be improved in order to ensure a longer durability. For this purpose, TaN monolayer and multilayer coatings were deposited on medical grade Ti-cp to enhance its tribocorrosion performance in simulated body fluids. TaN coatings were deposited by recently developed High Power Pulsed Magnetron Sputtering (HPPMS) technique. HPPMS enables the deposition of extremely dense coatings with superior properties compared to the ones grown by conventional sputtering. Columnar-free TaN monolayer and multilayer films were developed exhibiting corrosion resistances in the MΩ range, one order of magnitude higher than for Ti-cp. Friction coefficient of Ti-cp was reduced from 0.58 to 0.25 while wear rate was considerably decreased. The determined material loss after tribocorrosion tests for Ti-cp was 0.4 mm. It was reduced up to 1.55 × 10 mm by the application of best-performing TaN multilayer film., Financial support of this research program from the Basque Government (EMAITEK program) and Spanish National Department of the Education and Science in the projects: CSD2008-00323 FUNCOAT and MAT2014-57547-R is gratefully acknowledged.

A characterization study of nanoworm Au thin films fabricated onto Si (100) using an intermediate columnar porous silicon (PSi) layer is presented. The Au thin films are resistant to peeling in different buffers and solvents. Adhesion arises from the presence of a diffused Au nucleation layer in the channeled PSi, which can be observed even at short electroless Au deposition times. For longer deposition times, a gold surface film grows from piled and aggregated Au crystals, providing high surface area. X-ray absorption spectroscopy studies revealed differences in the Au L 3 absorption edge that can be ascribed to the induced nanoworm structure. The optical behavior of the Au grown on the surface has also been studied by light reflectance spectroscopy and related to the characteristic Au intra-band absorption. Such surfaces could enhance the performance of electric or optical devices with sensitivity limited by surface area availability.