Tattoos That Vanish

Researchers at the University of Colorado Boulder have made a groundbreaking discovery in the field of tattoo technology. They have developed an invisible tattoo ink that can be revealed with a UV torch and stays visible until switched off with white light. This innovative ink uses photochromic dyes, which change color when exposed to light.

The process of revealing and hiding the tattoo is quite straightforward. Two or three seconds of bright ultraviolet (UV) light is enough to form a new ring in the dye molecule, which switches a colorless pigment to a colored one. This means that the tattoo can be made visible in a matter of seconds.

The ink is not only innovative but also durable. It can undergo over 10,000 activation and deactivation cycles without degrading. This means that the tattoo can be revealed and hidden multiple times without losing its color or quality.

The researchers have published their findings in the journal Matter & Light. They have also created different motifs with this ink, ranging from a lantern that reveals its light when activated, to multicolored scales.

## Why it matters The development of this invisible tattoo ink has the potential to revolutionize the tattoo industry. It could allow people to have tattoos that are not visible in certain situations, such as in a professional setting, but can be revealed in social situations. This could be particularly useful for people who want to express themselves through tattoos but may face stigma or discrimination in their workplace or other areas of their life.

The use of photochromic dyes in this ink is also significant. These dyes have been used in color-changing sunglasses for years, but their use in tattoo ink is a new and innovative application. The fact that the ink can change color in response to light means that it has the potential to be used in a variety of different ways, from art to fashion to technology.