Researchers from the University of London (UCL) and the Italian Institute of Technology developed a smart tattoo that emits light and could be used to display information.
The tattoo uses organic light-emitting diodes (OLED), the same technology used in smartphones and televisions. It is applied in the same way as water transfer tattoos. That is, OLEDs are made on temporary tattoo paper and transferred to the skin or chosen surface by pressing and rubbing them with water.
It consists of a polymer that emits light when an electric field is applied between the electrodes. An insulating layer is then placed between the electrodes and the tattoo paper.
One of the advantages of the technology is that it can be used on flexible surfaces, can be made from liquid solvents, and can be printed. All of this makes it easy to develop custom OLEDs.
According to the researchers, this product could be used in combination with other electronic devices to, for example, emit light when an athlete is dehydrated, or when it is necessary to get out of the sun to avoid burns.
OLED tattoos could also be used for aesthetic purposes because they shine and add a decorative touch, but they could also be used in other areas such as food packaging to indicate when a product has expired.
“Our proof-of-concept study is the first step. Future challenges will include encapsulating OLEDs as much as possible to prevent them from rapidly degrading through contact with air, as well as integrating the device with a battery or supercapacitor.“, The professor analyzed Franco Cacialli, Professor of Physics and Astronomy at UCL, main author of the article, in a publication released by the university.
“In the healthcare sector, they could emit light when there is a change in a patient’s condition, or, if the tattoo was placed upside down on the skin, they could potentially be combined with light-sensitive therapies to attack cancer cells, for example”Added the researcher.
The OLED device is 2.3 microns thick overall, which is less than 400th of a millimeter or about one-third the length of a red blood cell; while the light-emitting polymer has a thickness of 76 nanometers. It should be noted that a nanometer is one millionth of a millimeter.
After having developed this technology, they placed the tattoos on a glass panel, a plastic bottle, an orange and a paper container, to test its operation.
“The advantage of this technology is that it is low cost, easy to apply and use, and washes away easily with soap and water.”, Highlighted professor Virgilio Mattoli, researcher at the Italian Institute of Technology and lead author of the research.
Tattoos with sound
A few years ago, tattoos with sound were surprising. This technology, known as Soundwave Tatto, was developed by Nate Siggard in Los Angeles. It consists of a sound wave permanently painted on the skin that a cell phone application reads and reproduces. This allows users to record phrases of loved ones and even fragments of melodies.
The user uploads a sound to the company’s website; the site generates the wave that is carried to the tattoo artist, who is then in charge of placing it on the skin. Although this technology was born in the United States, today this type of tattoos can be done in different parts of the world. On the company’s site called Skin Motion.