Self healing plastic
Over a period of time, composite materials such as plastics wear because of day-to-day usage, creating tiny cracks that continue to grow until the item breaks. But now Scott White, a materials engineer at the University of Illinois, Urbana-Champaign, USA,has created composites that can fix its own micro cracks before they have a chance to cause damage. White's plastic is full of tiny, liquid-filled spheres and dark specks of catalyst. A crack, located where the red and clear sections meet, breaks some of the spheres, whose contents congeal into a polymer and fill in the gap (www.discover.com, December 27, 2001).