Colour-changing hair dye and skin patches that show UV exposure Alex Mariakakis et al. 2020
Colour-changing stickers and hair dye that react to ultraviolet light could help people gauge when they are at risk of sunburn.
Alex Mariakakis at the University of Washington in Seattle worked with a team at Microsoft to develop printable stickers that change colour from purple to light pink throughout the day to indicate cumulative exposure to UV light. The patches contain a reference colour scale to indicate UV exposure, as measured by UV index (UVI) hours, a standard measure of UV radiation.
They also accommodate…