Salt, ice and some oomph — these three simple ingredients are all that’s needed to make waste-free electricity, researchers report September 15 in Nature Materials. Straining a single cone-shaped piece of ice that’s slightly smaller than a black peppercorn and 25 percent salt by weight can output about 1 millivolt, while an array of 2,000 cones could produce 2 volts, or enough electrical potential to power a small red LED.
The findings powerfully demonstrate the flexoelectric effect, a phenomenon where electricity is generated through the irregular deformation of a solid material. While the flexoelectricity produced by most materials is too weak for practical electrical systems, salted ice could someday