Steve Martin had a comedic routine focused on the idea of ”going small”. This probably did not inspire researchers at the Institute for Integrative Nanoscience when they set out to create a sub-millimeter microbattery. As you’d expect, you won’t be jumpstarting your car with a battery the size of a grain of sand anytime soon, but these batteries have a surprising amount of capacity.
The key is to create what they call “micro Swiss rolls” where the electrodes are wrapped in a small cylinder. It’s not a new idea. However, creating achievable scale rolls where a grain of rice looks huge is not trivial.
The combination of a zinc wire and manganese dioxide in minute proportions makes the battery possible. The manufacturing process is new and consists of making a slurry of MnO2 with a solvent. Placing the small Swiss roll on a glass substrate allows tiny circuitry to exist along the side of the battery. The battery itself is about the size of common SMD components, but the circuits it will power probably look more like tiny IC dice.
Building a better battery isn’t a new quest, although typically you don’t go for the small. We’re always on the lookout for new battery technology, even though most of what we read never appears on store shelves.