3D printer produces world’s tiniest battery

Nature : Not only is a new lithium-ion battery the smallest ever made, it is also the first battery created using a three-dimensional printer. No bigger than the head of a pin, the tiny battery could one day power small medical devices or miniature robots. Until now, 3D printers have been used primarily to create static plastic objects such as toys or prototypes of new designs or products. To create a functional object, the printer had to be customized to use a different building material. Lithium metal oxide nanoparticles were squeezed out like toothpaste to form a pair of microscopic interlocking five-fingered electrodes. To create the final product, successive layers of such electrodes were laid down one on top of the next. Gram for gram, the tiny battery stores as much energy as its larger counterparts. The fact that the battery could be tailored to suit a particular application makes it especially versatile.