MIT Nano-Battery

At present, battery size is a limiting factor in developing medical devices on the micro and nano scale.  However, this piece from MIT describes a 50 nanometer thick battery (with a smaller diameter than a human hair) that may be a great enabler.  ““The battery gains its charge by interacting with water molecules present in the surrounding air. When a water molecule comes in contact with the reactive, outer metal section of the battery, it is split into its constituent parts — one molecule of oxygen and two of hydrogen. The hydrogen molecules become trapped inside the battery and can be stored until they are ready to be used. In this state, the battery is “charged.” To release the charge, the reaction reverses. The hydrogen molecules move back through the reactive metal section of the battery and combine with oxygen in the surrounding air.”     MORE

Image Credit:  MIT: Nicole Fandel