Street art has become a mainstream cultural phenomenon, thanks to artists like Jean-Michel Basquiat, Keith Haring, Banksy and Kaws. But outdoor murals are vulnerable to vandals, who mar their beauty with unwanted graffiti. A group of chemists in Italy have developed a groundbreaking new method to wipe away graffiti while keeping the art underneath intact. The process involves loading nontoxic cleaners onto a thin sheet of polymers known as hydrogels ...