Patent applications reveal NASA is working on a biological nanobattery that uses the iron-containing protein ferritin to carry either a positive or negative charge:
A key problem is how to assemble a battery on such a tiny scale, and a number of research groups have been working on exploiting the way biological molecules self-assemble for this task.
NASA says one promising avenue is exploiting the ability of the iron-containing protein ferritin to carry either a positive or negative charge.
Ferritin also self-assembles relatively easily into a uniform nanolayer. So, the agency says, it is straightforward to create a layer of ferritin and then cover it with another layer of the opposite charge. The result is a capacitor just a few nanometres thick that can store charge between its layers - in other words a battery.
Adding more layers of alternately charged ferritin increases the capacitance of this bio-nanobattery. NASA reckons its battery is not only stable and robust, but can be produced easily and quickly too.