Engineers develop coating that detects bridge cracks using nanotechnology~

For bridge freaks like me, I think this is pretty cool. I'm not sure about the price though ($1/inch2), although if it prevents structural failure, it's probably worth it at any price: Michigan's Ann Arbor News (original article only available for fee) (9/3, Hamon) reports that Jerry Lynch, a University of Michigan professor of engineering, has led a research team in the development of structural coating that will "detect cracks in bridges before the damage is visible." According to the Ann Arbor News, Lynch and his colleagues created the coating with "carbon nanotubes that use electrical currents to find damage like strain and corrosion." Nicholas Kotov, a UM engineering professor and "key developer of the technology," explained that a "carbon nanotube is microscopic and shaped like a long, hollow strand of spaghetti." Moreover, it is "one of the strongest materials available and, when mixed with the polymers, lends strength to the coating." When electricity flows through the skin, "it produces a two-dimensional image via a central computing device," and "electrical resistance shown in the image will indicate structural damage." Kotov said that the "coating costs about $1 per square inch and is engineered to last decades." He added, "Presumably the carbon nanotube coating won't corrode over the lifetime of the bridge."