© Yuya Shino/Reuters/Corbis
In June, Harvard University scientists announced the creation of a seriously tiny lithium-ion battery that could one day power Lilliputian robots or mini medical devices. Created with a 3-D printer, the battery is so small that it can rest on the head of a pin.
Three-dimensional printers, headline makers in their own right in 2013, make objects by piling layer upon layer of material on top of each other. Most 3-D printers manipulate plastic, but the one that fashioned the midget battery relied on a new type of material crammed with lithium-metal-oxide particles.
The petite power source is less than a millimeter in size. It weighs less than 100 micrograms but is able to store as much energy per gram as the larger lithium-ion batteries that power items such as laptops and electric cars [source: Powell].