<\/p>\n
Arm tattoo before and after light activation. (Matter& Light, Bruns et al. via SWNS)<\/p>\n
By Talker<\/p>\n
By Stephen Beech<\/p>\n
A new generation of \u201cinvisible\u201d tattoos<\/a> switches on and off under different kinds of light.<\/p>\n American engineers who created the multicolored inks say they could one day help people hide their body art<\/a> when they have an important business meeting.<\/p>\n They could even doodle on their own skin<\/a> using a simple laser pointer, according to a study published in the journal Matter & Light<\/a>.<\/p>\n Lead author Carson Bruns said: \u201cTattooing is a very ancient technology that remains mostly untapped as a platform for today\u2019s technologies.\u201d<\/p>\n He explained that the new inks, known as PhotoTat, are made from dyes and a plexiglass-like material common in many medical technologies on the market today, including dermal fillers.<\/p>\n The research is a passion project for the biomedical engineering expert, who has a lot of his own tattoos \u2014 including a green lion on his arm.<\/p>\n Bruns, of the University of Colorado Boulder<\/a>, said: \u201cI love body art because of how personal it is.\u201d<\/p>\n To make the inks, he and his colleagues start with a material called polymethyl methacrylate, or PMMA, which forms incredibly small spheres that look like they\u2019re made of glass.<\/p>\n The team then inserts a range of color-changing dyes into the spheres.<\/p>\n Bruns said: \u201cBy mixing these primary colors, we can generate a full color image.\u201d<\/p>\n Normally, the dyes are completely invisible to the human eye.<\/p>\n But when an ultraviolet light is shined on them, they change color in just seconds \u2014 turning a vibrant blue, magenta or yellow.<\/p>\n The colors fade over several hours, but they can be switched off faster by exposing them to a bright LED light.<\/p>\n (Matter& Light, Bruns et al. via SWNS)<\/p>\n By Talker<\/p>\n Bruns said: \u201cPhotoTat is like a switch.<\/p>\n \u201cYou turn it on with UV light, but you can turn it off again when you go to grandma\u2019s house.\u201d<\/p>\n PhotoTat won\u2019t be available at any tattoo parlors<\/a> just yet, but Bruns and his colleagues hope to continue improving their designs in the coming years so that the inks become widely available for fans of body art.<\/p>\n<\/p>\n