image: X-ray of the hip region with a metal-on-metal implant superimposed, and a schematic illustrating graphitic material on the surface of the implant and an electron energy loss spectrum. The red spheres represent the positions of the carbon atoms in a single layer of graphite. The red spectrum is a spectrum of the energy lost by electrons going through the sample, which was the main tool used to determine that graphitic material was present. This image relates to a paper that appeared in the Dec. 23, 2011, issue of Science, published by AAAS. The paper, by Y. Liao at the Northwestern University in Evanston, IL., and colleagues, was titled, “Graphitic Tribological Layers in Metal-on-Metal Hip Replacements.” view more
Credit: Image © <i>Science</i>/AAAS