As if temporary tattoos weren’t cool enough already, new technology will actually enable them to emit light. So soon, you could potentially bedeck your skin in glowing, multicolored designs to match an outfit, or even just your jewelry for the night.

And according to the scientists behind this futuristic development, the applications for glowing tattoos go far beyond fashion. Everything from healthcare to sports and medicine could find a potential use for these water transfer tats.

“These could be for fashion — for instance, providing glowing tattoos and light-emitting fingernails,” explains Professor Franco Cacialli (UCL Physics & Astronomy), senior author of the paper. “In sports, they could be combined with a sweat sensor to signal dehydration.

“In healthcare they could emit light when there is a change in a patient's condition — or, if the tattoo was turned the other way into the skin, they could potentially be combined with light-sensitive therapies to target cancer cells, for instance.”

They could even be put on fruits or vegetables, to signal when the produce has gone bad, he says.

The fundamental tech behind these tattoos is not new — organic light-emitting diodes (OLED’s) were first used in TV screens 20 years ago and have been used in phones, computers and televisions ever since. However, this is the first time it’s been applied to any kind of tattoo technology.

The researchers created an “electroluminescent polymer” separating electrodes and covered with a layer of commercial tattoo paper. The device is just a mere 2.3 micrometers thick — just a third of the length of a single red blood cell. The tattoo is simply placed on the surface it’s intended for and dabbed with water. Just like those sick temporary tribal tattoos you’d get in grocery store vending machines — except these ones are cutting edge technology.

For the experiment, Cacialli and his team applied green light emitting tattoos to four different surfaces: a pane of glass, a water bottle, an orange and paper packaging, and then hit the switch.

And vioala! The tattoos began to glow for several seconds.

"Our proof-of-concept study is the first step,” says Cacialli. “Future challenges will include encapsulating the OLEDs as much as possible to stop them from degrading quickly through contact with air, as well as integrating the device with a battery or supercapacitor."

Obviously these new temporary tattoos have huge potential in futuristic fashion. People will be able to go to raves, clubs or hip parties matching that evening’s outfit and jewelry with the colors and designs of the glowing tattoos adorning their skin.

Perhaps most importantly, though, is the fact that there are also some really functional uses for this tech in sports, medicine and beyond, according to Cacialli. These tattoos could change the way the world looks and the way it works. And someday, he’s hoping they’ll be very cheap.

“The advantage of this technology is that it is low-cost, easy to apply and use, and washes off easily with soap and water."