New plastic bleeds and heals like human skin

A new plastic demonstrated to the American Chemical Society on Monday purports to be the first self-healing material to incorporate a damage-reporting mechanism, almost akin to the bleeding of human skin. "Our new plastic tries to mimic nature, issuing a red signal when damaged and then renewing itself when exposed to visible light, temperature or pH changes," said Professor Marek W. Urban, Ph.D of the University of Southern Mississippi. Urban's plastic contains molecular bridges that span the polymer chains that comprise the plastic. Should the plastic become damaged, these bridges break down; but when exposed to light (or a temperature or acidic vapor) these linkages are able to repair themselves. But additionally, Urban has rigged the bridges to change color - to red - when such damage occurs, with the color change fading away when the material repairs - essentially heals - itself. Such a material has obvious benefits when applied to consumer goods, such as laptops and mobile phones. Dropping the device would result in hairline cracks turning red, highlighting a need for repair (whereupon you need only expose the thing to intense light). But Urban also foresees heavier-duty applications: car fenders, aircraft components and even battlefield weapons systems among them (Urban has received U.S. Department of Defense funding for the research).
source: American Chemical Society