Time for sunscreen? Cavan Images/Getty
Our skin needs to get a certain amount of ultraviolet light to produce vitamin D, but how do we know when we have had too much sun? Wearables that change colour when exposed to UV light could tell us when we should put on sunscreen or seek shade.
Ali Yetisen at the Technical University of Munich in Germany and his colleagues created the wearables using liquid dyes that are sensitive to two types of UV radiation.
They used several different dyes that change colour when exposed to UVA …
