However, this isn't a silver bullet for infinitely renewable energy. At least not yet. The researchers conclude that other similar materials are more efficient, and that this breakthrough is more of a supplementary power source versus a primary one. "It is expected that with further compositional optimization, the properties will be improved and be more balanced, and thus will become more useful for multi-functional purposes," the paper reads.

All that to say, the scientists from the University of Oulu know there's still more work to be done before KBNNO is helping power smart cities or your next high-tech watch. The paper's lead author, Yang Bai, says that within the next year he should have a "multi-energy-harvesting" device prototype ready and in a few years the tech could be ready for the market.