GoKawiilResearchers develop light-activated tattoo ink that can be switched on and off
Scientists at the University of Colorado Boulder, led by Carson Bruns, created a tattoo ink system called PhotoTat that uses photochromic dyes in protective nanoparticles to appear or vanish depending on light exposure. A UV LED activates the colors within seconds, and they fade under bright sunlight, while the pigment itself stays permanently embedded in the skin. The research was published October 9 in the journal Matter & Light.