When forced into small cracks, water can be used in unexpected ways. A new battery design that relies on tiny amounts of water trapped within layers of clay could eventually provide sustainable power in extreme places like Mars.
Vasily Artemov and his colleagues at the Swiss Federal Institute of Technology built the battery using components similar to traditional batteries, including two electrodes: a negatively charged electrode and a positively charged electrode. But instead of making these electrodes out of metal, they…