Figure 1

SEM images of different titanium surfaces at magnification of 8000×. (a) Polished titanium surface. (b) Spear-type surface showing a dense nanostructure comprising short and thin spears. The inset shows a SEM image of a nano-spear with a cone-shaped cap taken at 100,000×magnification. (c) Pocket-type surface formed by intertwining of the longer and wider nano-spears.