Giving arrhythmic hearts a hug

Researchers at Northwestern University, the University of Illinois at Urbana-Champaign, and the University of Pennsylvania say they are the first to demonstrate a flexible silicon electronics device for a medical application.

Unveiled in the cover story of the journal Science Translational Medicine this week, the device not only bends, twists, and stretches, but it also produces high-density maps of a heart's electrical activity, an accomplishment that improves on conventional cardiac monitoring technology and could treat arrhythmia, the researchers say.

"The heart is dynamic and not flat, but electronics currently used for monitoring are flat and rigid," says Yonggang Huang, an engineering professor at Northwestern's McCormick School of Engineering and Applied Science and senior author of the paper. "Our electronics have a wavy mesh design so they can wrap around irregular and curved surfaces, like the beating heart...More contact points mean better data."

The device they tested in experiments on animal tissue at Penn is, at just 14.4 by 12.8 millimeters, about the size of a nickel, and manages to cram in 288 contact points and more than 2,000 transistors. (By comparison, standard clinical devices tend to have more in the range of 5 to 10 contact points.)

With all these contact points, the electronic circuitry is literally hugging the heart's tissue, enabling it to process more signals, faster. And while it's not wireless, researchers say the next step is to bring the power source to the device itself. The obvious source would be the closest, not to mention most poetic: the heart.

The team hopes the innovative material will lead to an entirely new generation of implantable medical devices, helping not only with abnormal heart rhythms and epilepsy but also photovoltaics, transmitters, microfluidic devices, and more.