Scientists have found that ice, one of the most common substances on Earth for centuries, can create electricity when unevenly bent or deformed.
A study published in Nature Physics has shown that ice can act as a flexoelectric(The flexoelectricity is considered as a property of a material that is called dielectric in which there is coupling between polarisation and a strain gradient.)
FLEXOELECTRIC ICE: A NEW EXPLANATION FOR LIGHTNING IN STORM CLOUDS
Ice blankets mountains, creates glaciers and defines polar landscapes.
The discovery came from an international team that included the Catalan Institute of Nanoscience and Nanotechnology (ICN2) in Barcelona, Xi’an Jiaotong University in China, and Stony Brook University in New York.
The scientists report the discovery isn’t a laboratory curiosity.
It could also be what makes thunderstorms act like they do. Lightning occurs when electrical charges accumulate in storm clouds.
Scientists had long known that ice collisions within clouds contributed to the process but couldn’t account for how ice itself possessed charge, as it is not piezoelectric.
The flexoelectric effect bridges that gap.
Scientists measured the electric potential that resulted from bending an ice block between two metal plates during the experiment.
The generation of electricity using the ice could help scientists with more developments in the future.
The measurements correlated with patterns that have been observed under cloud electrification. “We found that ice creates electric charge due to mechanical stress at all temperatures. Furthermore, we found that there is a thin ferroelectric layer on the surface below -113C,” explained Dr. Xin Wen at ICN2.
The surface properties are dramatic. It exhibits ferroelectricity, the capacity for reversing its electric polarity under an external field, at very low temperatures.
FROM POLAR REGIONS TO SPACE: TECHNOLOGICAL
Flexoelectricity is prominent at higher temperatures close to zero degrees.
That is, ice possesses two distinct mechanisms of generating charge based on conditions.
“This points to a natural explanation for the origin of lightning,” said Professor Gustau Cataln, who directed the Oxide Nanophysics Group at ICN2.
“The potential generated by deformed ice particles in collisions may be the missing link.”
The technological application is just as great. Flexoelectric materials like titanium dioxide are already being employed in sensors and capacitors.
Discovering the same in ice may hold the key to new uses, particularly where cold is a natural condition, like polar outposts or even space.
The research transforms a common material into something less common. Ice water, long thought to be straightforward, could now become part of the class of active materials that inform future technologies.
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