Nanogenerator Produces Electricity from Falling Snow

April 16, 2019 by Scott McMahan

Researchers at the University of California Los Angeles (UCLA) and collaborators have developed a new device that generates electricity from falling snow. According to the researchers, this small and thin, first-of-its-kind device, is flexible like a sheet of plastic and can be made inexpensively

"The device can work in remote areas because it provides its own power and does not need batteries," said senior author Richard Kaner, who holds UCLA's Dr. Myung Ki Hong Endowed Chair in Materials Innovation. "It's a very clever device — a weather station that can tell you how much snow is falling, the direction the snow is falling, and the direction and speed of the wind."

The research team refers to it as a snow-based triboelectric nanogenerator, or snow TENG. A triboelectric nanogenerator, which produces charge via static electricity, generates energy resulting from the exchange of electrons.

The team reported their findings about the device in the journal Nano Energy.

"Static electricity occurs from the interaction of one material that captures electrons and another that gives up electrons," said Kaner, who is also a distinguished professor of chemistry and biochemistry, and of materials science and engineering, and a member of the California NanoSystems Institute at UCLA. "You separate the charges and create electricity out of essentially nothing."

Snow Positively Charged

Notably, snow is positively charged and gives up electrons. Silicone, a synthetic, rubber-like material composed of silicon atoms and oxygen atoms, combined with carbon, hydrogen and other elements, is negatively charged. So, when falling snow meets the surface of silicone, it produces a charge that the device captures, generating electricity.

"Snow is already charged, so we thought, why not bring another material with the opposite charge and extract the charge to create electricity?" said co-author Maher El-Kady, a UCLA assistant researcher of chemistry and biochemistry.

"While snow likes to give up electrons, the performance of the device depends on the efficiency of the other material at extracting these electrons," he added. "After testing a large number of materials including aluminum foils and Teflon, we found that silicone produces more charge than any other material."

Winter Weather Reduces Solar Panel Output

Each winter, about 30 percent of the Earth's surface is covered by snow, and solar panels often fail to operate, El-Kady pointed out. In such environments, the accumulation of snow can reduce the amount of sunlight that strikes the solar array, restricting the panels' power output and rendering them less effective.

El-Kady speculates that the new device could be integrated into solar panels to deliver continuous power when it snows.

Device Could be Used in Wearables

According to Kaner, the device could be used to monitor winter sports like skiing, to more precisely assess and enhance an athlete's performance when jumping, running, or walking.

It could also identify the primary movement patterns in cross-country skiing, which cannot be detected with a smartwatch. The researchers envision its use in a new generation of self-powered wearable devices for tracking athletes and their performances. Such self-powered wearables would be able to send signals, indicating whether a person is moving or recognize when a person is walking, running, jumping.

The research team employed 3-D printing to design the device, which has a layer of silicone and an electrode to capture the charge.

The team believes the device could be made at a low cost given "the ease of fabrication and the availability of silicone," Kaner said.

Co-authors of include Abdelsalam Ahmed, who did the research while completing his doctoral studies at the University of Toronto; Ravi Selvaganapathy, and Islam Hassan of Canada's McMaster University; and James Rusling of the University of Connecticut along with his research team.

Funding for Kaner's research came from Nanotech Energy, a company spun-off from his research on which Kaner serves as the chair of its scientific advisory board and El-Kady is chief technology officer. Also and Kaner's Dr. Myung Ki Hong serves as the Endowed Chair in Materials Innovation.

In 2017, Kaner, El-Kady, and a team of researchers created a device that can use solar energy that can efficiently and inexpensively produce and store energy, which could power electronic devices and to generate hydrogen fuel for eco-friendly cars.

This year, they published research about their design of the first fire-retardant, self-extinguishing motion sensor and power generator.