Light-Up OLED Temporary Tattoos Pave the Way for Smarter Wearables
Scientists at UCL and the Italian Institute of Technology have created a temporary tattoo with light-emitting technology.
Researchers from UCL and the Italian Institute of Technology have developed temporary tattoos using OLED technology found in today’s TVs and smartphones, which could usher in a new type of smart tattoo with several different uses. While tattoos are generally displayed for artistic or personal expression, these new technological counterparts could have applications in the medical and agricultural industries. The OLED tattoos are applied in the same fashion as those you can buy from gum ball machines — by placing the tattoo on the skin, then dabbing it with water. Both use the same soluble paper base that slides the image, or in this case OLEDs, onto the skin when moisture is introduced.
The thin OLED device measures just 2.3 micrometers thick (less than one 400th of a millimeter) and features an electroluminescent polymer (a polymer that emits light when an electric field is applied) placed between a pair of electrodes. An insulating layer is sandwiched between the electrodes and the commercial tattoo paper, allowing the tattoo to make direct contact with the skin. The light-emitting polymer itself is just 76 nanometers thick and was produced using a spin coating technique, which is applied to a substrate, and then spun at high speed, producing an extremely thin and even layer, much like a crepe on a grill.
The researchers state that the new tattoos could be combined with other tattoo electronics for increased functionality, such as emitting light when an athlete becomes dehydrated or when to find shade to avoid sunburn. The OLED tattoos could also be placed on packaging or fruit to identify when a product has passed its expiration date when food is about to spoil or used for fashion in the form of wearable color-flashing artworks.