Tattoos are usually considered a form of personal expression, but one team of researchers in Europe have created what they call the world’s first luminescent tattoo based on OLED screen technology that not only looks cool, but can also serve as a visible warning of potential health problems.
T.attoos are used by people for their dedication to a long-extinct MP3 player brand or let everyone know how much they love their mothers. B.But there is also precedent for using tattoos as a medical device. Cancer patients undergoing radiation therapy are tattooed with tiny dots that are used as reference markers for precise targeting of the machines used for treatments during refresher sessions, for example
The idea of personally enhancing your skin with radiant art isn’t new either, but previously this was involved biohackers implantation technologies like LEDs under the skin, and the results don’t have much practical use aside from glaring or inviting questions about why someone would do that to themselves. This new approach to luminous tattoos is easier to apply, more practical and more temporary – without the need for surgery to have it removed.
In a recently published article in the journal Advanced Electronic Materials, Ultra-thin, ultra-compliant and freestanding tattooable organic light-emitting diodes scientists of the University College London in the United Kingdom and the Italian Institute of Technology detail how their new approach to tattoos is based on the same organic light-emitting diode technology used in devices such as more recent iPhones, as well as the recent crop of mobile devices with folding screens. The flexibility of an OLED screen is important for this application as human skin is so pliable and bends and folds as the body moves.
G / O Media can receive a commission
The actual electronics of the luminescent tattoos, made of an extremely thin layer of an electroluminescent polymer that glows when a charge is applied, measures just 2.3 microns thick, which the researchers say is about a third of the thickness. diameter of a red blood cell. The polymer layer is then sandwiched between a pair electrodes and sits on top of an insulating layer, which is attached to temporary tattoo paper through a printing process that is not prohibitively expensive. The tattoos can be easily applied to surfaces using the same wet transfer process that temporary tattoos for kids use, and can be easily washed off when no longer needed or desired with soap and water.
With a current applied, the OLED tattoos just glow green in their current form, but could eventually produce any color using the same RGB approach that OLED displays use. While the researchers recognize that the potential for glowing tattoos is there, taking art in a whole new direction, they also see even more potential for them as a medical device. In conjunction with other wearable technologies, the luminescent tattoos can flash when an athlete needs to rehydrate, or change color when applied to food, providing clear warnings when the expiration date has passed.
But don’t walk to your local tattoo parlor and just claim one of those beautiful new glowing tattoos. The researchers have successfully applied them to surfaces such as glass, plastic bottles, paper and even oranges so far, but human skin poses more of a challenge given the amount of people who are constantly on the move. The OLED polymers can also degrade quickly when exposed to air, requiring additional layers to properly encapsulate and protect them, and there is an even greater problem finding a way to power them. with small batteries or supercapacitors, as they have been connected to an external power source so far in the lab, and it is doubtful anyone would want to connect a USB power cable to the ink on their arms.