'Electronic' Skin Monitors Heart, Brain Function

U.S. researchers have developed a stretchy, ultra-thin, self-adhesive material that contains miniature electronics to monitor heart activity, brain waves and muscle movement.

According to scientists, the new stretchy skin technology, epidermal electronics system (EES), is able to monitor key body functions without the use of cumbersome wires and glues since it attaches to the skin without adhesive.

The material bends, wrinkles and stretches with all the properties of skin. Yet it contains an array of electronic components that can measure everything from heart rate to brain waves. The so-called "smart" skin is powered by a solar cell.

It was developed by scientists at the University of Illinois, Northwestern University in Illinois, Tufts University in Massachusetts, the Institute of High Performance Computing in Singapore and Dalian University of Technology in China.

John Rogers, professor of materials science and engineering at the University of Illinois Urbana-Champaign, is the project's lead researcher. He says the electronically-embedded material, which can be placed anywhere on the body, is no thicker than a human hair and is difficult to handle. But they figured out a way around the problem.

"The way that we actually mount these devices on the skin uses ideas borrowed directly from kids' temporary transfer tattoos," says Rogers, "which is that the device is so floppy, and flexible and skin-like that you can't mechanically manipulate them effectively. You grab them on one edge and they kind of collapse and crumple under their own weight."

So the researchers mounted the "smart" skins onto thin, water soluble polymer backings. After the epidermal electronics device is applied face down onto real skin, the backing is rinsed away.

Rogers says researchers even used temporary tattoos as the backing.

"Temporary tattoos are already low cost, the materials have been worked out, the adhesion is good, why not just use that materials technology as a substrate. And oh, by the way, it provides a way to conceal the electronics to the extent that might be interesting for certain applications."

Depending on where the "smart" skin is applied, Rogers says it's possible to monitor the heart's electrical activity, the contraction of muscles in the arm or the electrical activity of the brain.

"It also turns out that that data can be used as a type of human-machine interface for controlling computer systems, for example. And we demonstrated that concept using electrical activity measured on the throat as the wearer was speaking different words to control a cursor in a simple computer game."

Researchers say the technology could be helpful to people with neuro-muscular diseases like Lou Gehrig's disease.