Scientists Work to Develop a Light-emitting Tattooable Technology

Scientists from the University College London (UCL) and the Istituto Italiano di Tecnologia (Italian Institute of Technology, IIT) have developed a new “tattooable” technology that allows organic light-emitting diodes to be applied onto surfaces including skin in the same way water transfer tattoo would be. This new technology has the potential to be used for a variety of applications within healthcare, fashion, sport, and potentially more. 

 

UCL and IIT scientists develop ultrathin OLED tattooable technology. Image used courtesy of Barsotti – Italian Institute of Technology

 

OLED Technology

OLEDs are solid-state devices that are made up of thin films of organic molecules that can generate light with the application of an electric current. The advantage of using OLEDs is that they produce brighter and much clearer displays on electronic devices than conventional LEDs or liquid crystal displays (LCDs) currently available on the market. OLEDs also have the advantage of requiring much less power to operate than LEDs or LCDs. OLEDs are currently used to create digital displays for computer monitors, television screens, smartphones, consoles, and more. 

 

Tattooable OLEDs

In their paper published in Advanced Electronic Materials, the UCL and IIT researchers detailed the process of how the tattooable OLEDs were fabricated and commented on the potential applications of the technology. The non‐encapsulated, green‐emitting OLED device developed by the researchers was fabricated on top of a commercial temporary tattoo substrate. It measured 2.3 micrometers in thickness, which is about a third of the length of a single red blood cell. The OLED device consists of a  light-emitting polymer known as an electroluminescent polymer, which is sandwiched between two electrodes. An insulating layer is also present and is placed between the electrodes and the commercial tattoo paper. A technique known as spin coating was used to create the light-emitting polymer and involves the spinning of the polymer on a chosen substrate at high speed. This achieves an even, ultrathin polymer layer. Once created, the tattooable OLEDs were applied to paper packaging, a pane of glass, an orange, and a plastic bottle.

 

UCL and IIT scientists develop ultrathin OLED tattooable technology. Image used courtesy of Barsotti – Italian Institute of Technology

 

In a news release,, the Senior author of the paper, Professor Franco Cacialli (UCL Physics & Astronomy and London Centre for Nanotechnology at UCL), said: “The tattooable OLEDs that we have demonstrated for the first time can be made at scale and very cheaply. They can be combined with other forms of tattoo electronics for a very wide range of possible uses. These could be for fashion – for instance, providing glowing tattoos and light-emitting fingernails. In sports, they could be combined with a sweat sensor to signal dehydration. Cacialli added: “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.

In the same news release, senior author and IIT researcher, Dr. Virgilio Mattoli, said: “Tattoo electronics is a fast-growing field of research. At the Italian Institute of Technology, we have previously pioneered electrodes that we have tattooed onto people’s skin that can be used to perform diagnostic tests such as electrocardiograms. The advantage of this technology is that it is low-cost, easy to apply and use, and washes off easily with soap and water.”