a new material that changes color when stressed or stretched. This cholesteric liquid crystal elastomer (CLCE) won't be in a 3D printing material shop anytime soon, but researchers at the Univ. of Pennsylvania say this material may solve industry problems in smart sensing, displays, and robotics across medicine, diagnostics, monitoring, and can even be used in art. "This could allow us to observe mechanical stress in a way that was previously impossible with traditional materials," says Shu Yang, lead investigator of the work.