New research has just been reported this week on coffee rings, those messy brown circles left on your table or coaster by drips from your cup. Now scientists have replicated them to find a nanoscale low-cost method of diagnosing illness. ROASTe first brought coffee ring science to your attention this past November (http://www.roaste.com/CafeRoaste/News/2010/11/26/Rings-Speak). Since we’re positive you’re waiting for the sequel to all coffee ring revelations, we now post the long-awaited update. Researchers took the idea of coffee ring formation and transferred the canvas from a coaster to glass slides. The theory was that the rings would be distinguished by the size of the beads left by evaporating drops. The largest particles would dry in the innermost rings, while the smallest would dry in the outermost rings. With the help of a chromatograph, the researchers next found that the technique could be used to separate proteins, bacteria, and mammalian cells in an aqueous mixture. Okay, that’s as close to Physics as we want to go, but the important thing here is that this can be done without a power source. The application to diagnosing of disease in developing countries is the part that excites the researchers. As one of them said, “Separation is a critical step in disease diagnostics to help identify the culprit of an illness.” From rings on a napkin to identifying the bacteria behind a disease – coffee – you just gotta love it.