Flexible LED Sheets To Enable Glowing Tatoos

US researchers announce the development of a new type of technology, that could in the near future be used to enable a host of biomedical applications, as well as glowing tattoos.

The team developed light emitting diodes (LED) with a twist, literally. Scientists managed to obtain thin, flexible sheets of LED devices, that can be safely inserted under the skin to produce glowing tattoos.

The group included expert John Rogers from the University of Illinois in Urbana-Champaign (UIUC), as well as scientists from China, Singapore and South Korea, Chemistry World reports.

In order to make the LED arrays flexible, the team selected to use a low cost, flexible, biocompatible polymer as a substrate. Polydimethylsiloxane (PDMS) seemed like an obvious choice.

Scientists started out by using circuit arrays just 2.5 micrometers thick, and 100 x 100 micrometers in size. They then printed the electronics onto glass, before transferring them to the PDMS substrate.

Rogers believes that this work is very relevant for the medical industry, and says that his group will continue with the investigation regardless of the fact that the scientific community is now focusing on organic LED (OLED).

“I wouldn't necessarily characterize this approach as better [than OLED]. OLED are extremely sensitive to oxygen or water, but we encapsulate our device in a thin layer of silicon rubber,” the expert says.

“The brightness, lifetime and the ability to make them in a waterproof form distinguishes our devices,” Rogers goes on to say.

In experiments conducted with the new arrays, the team inserted the miniature devices in a soapy water solution, and then under the skin of an animal model. The LED endured these conditions without damage.

“We're used to thinking of electronic devices as distinct from things we wear or put over our wounds to heal them,” explains expert Michael Strano.

“Nobody knows what's going to come from a lot of this work, but it's going to have an enormous impact,” says Strano.

The expert holds an appointment at the Massachusetts Institute of Technology (MIT) Chemical Engineering Department.

“We try to choose problems in science where the solutions can have an impact on society through commercialized products. I want to see this stuff have impact - it's the end goal that's serving as a motivation,” Rogers concludes.