To create the microbattery, a custom-built 3D printer extrudes special inks through a nozzle narrower than a human hair. Those inks solidify to create the battery's anode (red) and cathode (purple), layer by layer. A case (green) then encloses the electrodes and the electrolyte solution added to create a working microbattery. [Credit: Ke Sun, Bok Yeop Ahn, Jennifer Lewis, Shen J. Dillon]
To create the microbattery, a custom-built 3D printer extrudes special inks through a nozzle narrower than a human hair. Those inks solidify to create the battery's anode (red) and cathode (purple), layer by layer. A case (green) then encloses the electrodes and the electrolyte solution added to create a working microbattery. [Credit: Ke Sun, Bok Yeop Ahn, Jennifer Lewis, Shen J. Dillon]
For the first time, a research team from the Wyss Institute at Harvard University and the University of Illinois at Urbana-Champaign demonstrated the ability to 3D-print a battery. This image shows the interlaced stack of electrodes that were printed layer by layer to create the working anode and cathode of a microbattery. [Ke Sun, Teng-Sing Wei, Jennifer Lewis, Shen J. Dillon]
For the first time, a research team from the Wyss Institute at Harvard University and the University of Illinois at Urbana-Champaign demonstrated the ability to 3D-print a battery. This image shows the interlaced stack of electrodes that were printed layer by layer to create the working anode and cathode of a microbattery. [Ke Sun, Teng-Sing Wei, Jennifer Lewis, Shen J. Dillon]

The printed microbatteries could supply electricity to tiny devices in fields from medicine to communications, yet provide enough stored energy to power them.

To make the microbatteries, a team based at Harvard University and the University of Illinois at Urbana-Champaign printed precisely interlaced stacks of tiny battery electrodes, each less than the width of a human hair.

"Not only did we demonstrate for the first time that we can 3D print a battery, but we demonstrated it in the most rigorous way," said Jennifer Lewis, PhD, senior author of the study, and Hansjörg Wyss professor of biologically inspired engineering at the Harvard School of Engineering and Applied Sciences (SEAS). Dr Lewis is also a core faculty member of the Wyss Institute for Biologically Inspired Engineering at Harvard University. 

To create the microbattery, a custom-built 3D printer extrudes special inks through a nozzle narrower than a human hair. Those inks solidify to create the battery's anode (red) and cathode (purple), layer by layer. A case (green) then encloses the electrodes and the electrolyte solution added to create a working microbattery. The inks contain nanoparticles of a lithium metal oxide compound that give the anode the proper electrical properties. The printer deposits the inks onto the teeth of two gold combs, creating a tightly interlaced stack of anodes and cathodes. Then the researchers packaged the electrodes into a tiny container and filled it with an electrolyte solution to complete the battery.

The work was supported by the National Science Foundation and the DOE Energy Frontier Research Center on Light-Material Interactions in Energy Conversion.