3D printers make microbatteries

This image shows the interlaced stack of electrodes that were printed layer by layer to create the working anode and cathode of a microbattery. CREDIT: Ke Sun, Teng-Sing Wei, Jennifer Lewis, Shen J. Dillon  View full size image

Good new, techies: 3D printers can now do more than make dust-collecting doodads. Researchers have developed a method of producing powerful microbatteries using these trendy contraptions.

Developed by a team of researchers at Harvard University and the University of Illinois at Urbana-Champaign, these lithium-ion microbatteries are no bigger than a grain of sand but hold as much energy as their much larger counterparts.

"The electrochemical performance is comparable to commercial batteries in terms of charge and discharge rate, cycle life and energy density," said Shen Dillon, assistant professor of materials science and engineering at the University of Illinois at Urbana-Champaign. "We're just able to achieve this on a much smaller scale."

To create the microbatteries, researchers used a custom-built 3D printer to stack electrodes- each one less than the width of a human hair- along the teeth of two tiny gold combs. The electrodes were contained within a special ink, extruded from the printer's narrow nozzles and applied to the combs like toothpaste being squeezed onto a toothbrush.

The electrode inks- one serving as a cathode, the other as an anode- hardened immediately into narrow layers, one atop the other. Once the electrodes were stacked, researchers packaged them inside tiny containers and added an electrolyte solution to complete the battery pack.

This novel process created a battery that could one day help power tiny medical implants as well as more novel electronics, like flying, insect-like robots. Such devices have been in development for some time, patiently awaiting an appropriately-sized power source.

"[The researchers'] innovative microbattery ink designs dramatically expand the practical uses of 3D printing, and simultaneously open up entirely new possibilities for miniaturization of all types of devices, both medical and non-medical," said Donald Ingber, the founding director of the Wyss Institute for Biologically Inspired Engineering at Harvard.