3-D printed lithium-ion microbatteries developed by researchers at Harvard and Illinois could supply electricity to tiny devices in fields from medicine to communications, including many that have lingered on lab benches for lack of a battery small enough to fit the device, yet providing enough stored energy to power it. To make the microbatteries, a team printed precisely interlaced stacks of tiny battery electrodes, each less than the diameter of a human hair. The results of the research were published June 18 in the online journal Advanced Materials.