Liquid metal in hydrogel generates electricity with a twist

“Mechanical energy – such as the kinetic energy of wind, waves, body movement and vibrations from motors – is abundant,” said Michael Dickey, corresponding author of a paper on the work and Camille & Henry Dreyfus Professor of Chemical and Biomolecular Engineering at NC State. “We have created a device that can turn this type of mechanical motion into electricity. And one of its remarkable attributes is that it works perfectly well underwater.”

The heart of the energy harvester is a liquid metal alloy of gallium and indium that is encased in a hydrogel.

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The water in the hydrogel contains ions that assemble at the surface of the metal, which can induce charge in the metal. Increasing the area of the metal provides more surface to attract charge. This generates electricity, which is captured by a wire attached to the device.