There is a new material that can heal itself in case of a scratch. It uses a concentrated polymeric ink, which flows out of a vascular system that mimics our own skin. The healing stops after seven cycles but "this limitation might be overcome by implementing a new microvascular design based on dual networks."
Right now it can heal small cuts but researchers are working in networks that "can heal 'lacerations' that extend into the material's substrate." That probably means indestructible killing robots or sexy ninja vixens. Or for extra fun, both.