Li-ion microbatteries produced via 3D printing

Lithium-ion microbatteries the size of a grain of sand can be manufactured using 3D printing and could supply electricity to tiny devices used in medical and communications fields, says a group of researchers from Harvard University and the University of Illinois at Urbana-Champaign. The team printed precisely interlaced stacks of tiny battery electrodes, each less than the diameter of a human hair to create the microbatteries.

In recent years engineers have invented many miniaturized devices, including medical implants, flying insect-like robots, and tiny cameras and microphones that fit on a pair of glasses. But often the batteries that power them are as large as or larger than the devices themselves-which defeats the purpose of building small.

To get around this problem, manufacturers have traditionally deposited thin films of solid materials to build the electrodes. However, because of their ultra-thin design, these solid-state micro-batteries do not pack sufficient energy to power tomorrow's miniaturized devices.

Figure 1: Interlaced stack of electrodes that were printed layer by layer to create the working anode and cathode of a microbattery.

The scientists realised they could pack more energy if they could create stacks of tightly interlaced, ultrathin electrodes that were built out of plane. For this they turned to 3D printers which follow instructions from three-dimensional computer drawings, depositing successive layers of material or inks to build a physical object from the ground up, much like stacking a deck of cards one at a time.

1???2??