Researchers have developed a breakthrough tattoo ink that can be instantly activated and erased using ultraviolet light and sunlight, respectively. The pigment remains embedded in the skin but changes visibility within seconds when exposed to specific light conditions. This reversible process could revolutionize temporary body art, medical markings, or even anti-counterfeiting applications. The discovery marks a significant advancement in light-responsive materials for practical use.
A 365-nanometer ultraviolet LED can switch a tattoo pigment on in about two to three seconds, and bright sunlight erases the color again within seconds, even though the pigment stays in the skin. That ...
