Powering a Pacemaker with the Heart it Keeps in Rhythm

The implant contains a flexible piezoelectric film and a tiny rechargeable battery. (Credit: John Rogers, University of Illinois)

The implant contains a flexible piezoelectric film and a tiny rechargeable battery. (Credit: John Rogers, University of Illinois)

It’s beginning to become pretty apparent to me that Yonggang Huang of Northwestern University and John Rogers of the University of Illinois are two of the biggest science rock stars in the Big Ten. And when you put the two of them together in collaboration, amazing things will soon follow. The duo have a longstanding collaboration that researchers flexible electronics.

Take, for example, my post from 2011 about stick-on “tattoos” that are basically fully functioning, wireless computer chips just 40 micrometers thick that stick to human skin without any sort of adhesive. These could act as an EEG or EMG sensor to monitor nerve and muscle activity, or a sensor to monitor brain waves, sleeping patterns and other brain functions. Current methods require sticky gel pads to be placed all over the body with long, clunky wires attached to computers and power sources. But the new electronic tattoos have all of that built in. You could walk around all day, sleep on your sofa and go for a run without even noticing that you’re wearing medical devices.

Or there’s my post from 2012 on similarly thin electronic strips with all the wiring embedded that dissolve away completely in the presence of water. The possibilities are endless. Medical implants – sensors or thermal therapeutic devices, for example – could simply vanish once they are no longer needed. Environmental sensors could be deployed without the need to retrieve them ever. Hell, cell phones could disintegrate away into thin air once the next model gets released.

Or the post from 2013 on radically new camera lenses that integrate many cameras on a spherical surface much like a bug’s eye to create a wide field of vision. Again, flexible electronics that can conform to the shape of a sphere were integral to the project.

Well, they’re at it again, folks, this time with some piezoelectric magic.

Piezo comes from the Greek word for pressure, while electric means exactly what you think it is. So these materials are able to generate electricity through the pressures exerted on them and the deformations those pressures cause. There are a lot of projects out there trying to harness energy from wearable electronics embedded in your shoes or clothing, so that natural everyday movements could charge electronic devices.

But for their new project, Huang and Rogers went for something even more intrinsic to your everyday life – the beating of a human heart.

The duo have now demonstrated a thin-film, all-in-one electronic device that can adhere to the surface of a heart and generate electricity from its constant beating. Such a device could power pacemakers, defibrillators and heart-rate monitors naturally and reliably and reduce or eliminate the need for batteries.

You could see this sort of advance coming by looking at their previous work. Thin film electronics, biocompatible materials, adhesive films—it all adds up to implantable microdevices. In their study, the team attached their prototype to the hearts, lungs, and diaphragms of living animals and produced enough electricity to charge a 3.8-volt battery.

“This work is a great demonstration of engineers working with doctors and taking advantage of the natural properties of a beating heart,” Huang said. “We envision this device being used to power a pacemaker with the energy coming right from the heart.”

With a proof-of-concept in the bag, the pair are now working to optimize different design layouts of the stretchable mechanical energy harvester to facilitate its easy use. This is step one toward having everything mentioned above actually available in humans.

So stay tuned.

The paper, “Conformal piezoelectric energy harvesting and storage from motions of the heart, lung, and diaphragm,” was published in the Proceedings of the National Academy of Sciences by Huang and Rogers, and, of course, an entire slew of brilliant team members.


About bigkingken

A science writer dedicated to proving that the Big Ten - or the Committee on Institutional Cooperation, if you will - is more than athletics.
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