While many technologies have been shrinking in size every year, one technology resistant to such advancement is the battery that powers the miniaturized technologies. Some means of building small-scale batteries have been developed, but these often do not have the power to drive the latest devices. Researchers at Harvard University and the University of Illinois at Urbana-Champaign however have designed a new micro-scale battery that can actually be printed.
The traditional small-scale batteries have electrodes made of thin films, which are able to store some, but not a lot of energy, due to their ultra-thin design. The new battery however is 3D, which allows it to store considerably more energy. To create it the researchers had to build a special 3D printer to extrude the inks in the right places. The inks in this case contained nanoparticles of one lithium metal oxide or another, depending on if the electrode being printed at the time is the anode or cathode. Once printed, the two interlacing electrodes are then placed in a container and flooded with the necessary electrolyte.
Though the battery is on the order of micrometers, it actually has many properties comparable to the larger battery we use every day, including charge and discharge rate and energy density. Of course because the battery is so small, it holds considerably less energy, but the modern and future devices it will power will also be small.