A material heals itself

Imagine: Your 6-year-old found a nail in the garage and drew pictures across the side of your new car. Gnash your teeth now, but researchers say the fix-up may be cheap and easy to do yourself in the not-too-distant future. They have developed a polymer-based material that can heal itself when placed under ultraviolet light for less than a minute. The scientists envision that re-healable materials like theirs could be used in automotive paints, varnishes for floors and furniture, and many other applications. Their polymers aren't ready for commercial use, they acknowledge, but prove that the concept works. "These polymers have a Napoleon Complex: in reality they're pretty small but are designed to behave like they're big by taking advantage of specific weak molecular interactions," said Stuart Rowan, on of the responsables of the project. "Their molecular design allows the materials to change their properties in response to a high dose of ultraviolet light," said Christoph Weder, researcher.