Oxide layers formed by micro-arc oxidation (MAO) using direct current electrolysis and pulse electrolysis were characterized by scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and adhesive strength measurements. Ti oxide films fabricated by pulse electrolysis were found to have a significantly higher adhesive strength than those fabricated by direct current electrolysis. This can be explained by the different interface adhesive strengths between the two Ti oxide layers and the Ti substrate, as revealed by cross-sectional SEM micrographs. In addition, the dependences of the voltage and the current on the electrolysis time were investigated.

Micrometer-scale patterning of a sol-gel derived TiO 2 film was formed on a titanium plate using photo-irradiation patterning. The patterned TiO 2 on a micrometer scale, which had nearly the same design as the TiO 2 gel film, was formed at pulsed-current density by anodic oxidation in an alkaline bath under spark discharge.

Fabrication of a new ball-shaped titanium material for vertebral compression fracture treatment has been studied using micro-arc oxidation in an electrolyte containing hydroxyapatite (HAp). To prevent microstructural disturbance on the surface, ethanol was used as a co-solvent. The material thus obtained was found to have high porosity with many micropores, fixed HAp particles on the surface, and elasticity comparable to cancellous bone. Furthermore, it was demonstrated that the materials have osteoconductivity and the elasticity was kept under cycled stress. These indicate that they can be new bone filling materials for percutaneous vertebroplasty (PV).

The patterned titania gel film fabricated by UV-irradiation through a mask and leaching was anodized by direct current electrolysis or pulse electrolysis. The patterning prepared through the two electrolyses was quite contrasted in that masking part and unmasking part was anodized in direct electrolysis and in pulse electrolysis, respectively. In addition, the oxide film thickness obtained using pulse electrolysis was thinner than that using direct current electrolysis. Thus, a combination of the photopatterning and pulse electrolysis made it possible to fabricate hydroxyapatite (HAp)-fixed and thinner titanium oxide film with fine pattern on titanium plate.