Courtesy of Jennifer Lewis
A tiny electrodes stack printed with a custom 3D printer to create the anode and cathode of a microbattery.
As technology improves, it usually shrinks. But rarely to the size of a grain of sand.
That’s about how small the microbatteries researcher Jennifer Lewis will be working on at Wyss Institute for Biologically Inspired Engineering at Harvard University.
Lewis recently unveiled super-small batteries, which she developed at the University of Illinois at Urbana-Champaign, that could power miniature medical devices, insect-sized robots, micro-cameras, and even minuscule sensors know as “smart dust.”
“There really is a need for these,” said Lewis, principal investigator in the research, who recently accepted a joint appointment with the Wyss Institute and Harvard’s School of Engineering and Applied Sciences.
Her group in Illinois originally set out to show that 3D printing technology could be used to create batteries small and powerful enough to run a growing number of devices that scientists have been working on for years but unable to operate without equally tiny power sources. For instance, she said, these microbatteries could potentially be used in RoboBees, the small robotic insects that are also being developed at Harvard. Lewis’s initial batteries are actually too small for the robotic bees, which are about half the size of a paper clip and weigh less than a tenth of one gram.
The project wasn’t just meant to show that 3D technology can create extremely small forms, said Lewis, but also that 3D printers can make things with more than just plastic “inks.” Commercially available printers from companies such as MakerBot Industries typically extrude plastic filament to create physical forms from digital files.
For this project, Lewis and her team built a custom 3D printer to extrude highly-specialized conductive materials from a nozzle smaller than the size of a single strand of human hair, that when set, combined with an electrolyte solution created a power source.