Tribological Properties of Hip Implant From Atomic Force Microscopy

Mechanical and tribological properties of engineering and biological materials have been investigated at micro-scale levels from Atomic Force Microscopy (AFM) [1]. Regarding the tribological properties of engineering and biological materials such as the diamond-like carbon (DLC) film [2], the TiN film [3], and the surface of middle finger [4], the significant effect of their surface roughness on the frictional coefficient has been reported. However, the contradictory result that the relationship between the surface roughness and frictional behavior of the self-assembled monolayer (SAM), the silicon ruler, and the metal evaporated (ME) tape [5] is not significant has also been reported. Therefore, the main goal of this study is to investigate the relationships between the surface roughness, the frictional coefficient, and the hardness for both the main wear and the least habitual wear regions of the cobalt-chromium metal head of the hip implant from their measurements using AFM and Hardness Testing Machine. With the additional wear measurements of the metal head, the result of this study can help to understand how the micro-scale surface structure of the metal head affects its wear.