It’s the century of smalls, where tiny devices are top dog. Computers shrink into tablets, phones are limited only by screen size, and mini-microphones can fit onto a pair of spectacles or atop a tiny flying robot. Why not? If you’re going to bug someone, you may as well use a robot bug.
As microchips become more and more micro, one thing holding us back is the battery. To get a decent battery life, you still need a rather large and heavy battery. Even my humble Nokia (circa 2002, still works like a charm) is half as heavy if you take out the battery. Think how light my pocket could be with a better battery!
Light pockets are one thing, a light heart is another.
Pace makers depend on lithium iodine-polyvinylpyride batteries, and they must be reliable and long-lasting.
“The battery occupies major portion of the pulse generator in terms of weight, volume, and size. The most important factor for a cardiac pacemaker battery is its reliability. Unlike many consumer products, batteries in implantable devices cannot be replaced. They are hard wired at the time of manufacture before the device is hermetically sealed… In general the power source of the implantable device is the only component which has a known predictable service life, which in turn determines the service life of the implanted device itself.” – Mallela, Ilankumaran & Rao “Trends in Cardiac Pacemaker Batteries” Indian Pacing and Electrophysiology Journal.
Don’t get me wrong, batteries have come a long way over the past twenty years. But there’s always more juice to be squeezed, and when it comes to juicy technology you can’t go past the 3D printer.
To make the sand-sized batteries, a team from Harvard University and the University of Illinois printed layers of concentrated lithium oxide-based inks. The 3D printer squeezed out tightly interlacing anodes (red) and cathodes (purple) using a nozzle finer than a human hair. The ink hardened as it was placed. Then they enclosed the stacks of electrodes in a container and filled it with an electrolyte solution.
Tests showed some impressive results for battery performance.
“The electrochemical performance is comparable to commercial batteries in terms of charge and discharge rate, cycle life and energy densities. We’re just able to achieve this on a much smaller scale,” Researcher Shen J. Dillon, University of Illinois, said in the press release.
Tiny and powerful batteries could make all sorts of new devices possible. Medical devices used not just for treating illness, but also for sensing infection or blood sugar levels, perhaps. Iron Man suits, now that would be exciting. And wafer-thin laptops, tablets and phones. Maybe I’ll wait until these new batteries hit the market before I update my Nokia…
Sun, K., Wei, T., Ahn, B., Seo, J., Dillon, S., & Lewis, J. (2013). 3D Printing of Interdigitated Li-Ion Microbattery Architectures Advanced Materials DOI: 10.1002/adma.201301036