"Researchers at the University of Illinois created microcapsules a mere 10 microns across, filled with a liquid metal alloy. They then bonded these capsules to the conductive material of a multilevel circuit (gold, in this case). When the circuit was bent to the point where the conductive line broke, the capsules also ruptured, and the liquid metal entered the crack, bringing the circuit back to life in less than 1,000th of a second. The microcapsules need to be made even tinier before they can be commercially applied, but the approach could also lead to batteries that fix themselves." - Adriano from Bookmarklet