Researchers Biswajit Ghosh and Marek W. Urban at the University of Southern Mississippi have come up with a new polymer compound that repairs itself if damaged. The best part is that it is made (in part) using a natural material derived from the shells of crustaceans, chistosan. The main component of this polymer chain is a polyurethane, a polymer group familiar to most of you as the varnish used for protecting your wood deck. However, polyurethanes are also used for a number of other products, depending on the manufacturing method: car seats, dashboards, watchbands, tennis racket grips, and even upholstery or bedding. In addition to chitosan, Ghosh and Urban have added oxetane, a four-membered ring.
When this polymer network is physically damaged, the oxetane rings open up to reveal two reactive ends. Upon exposure to UV light, the chitosan chains are effectively "snipped," forming crosslinks with the reactive ends on the oxetane, repairing the network. This is capable of happening in under an hour.