An international team of scientists from the United States, Canada, Egypt and Ireland has developed a snow-based triboelectric nanogenerator (TENG) that generates electricity from falling snow. The snow-TENG, described in the magazine. Nano energy, can produce a power density of 0.2mW / mtwoand open circuit voltage of up to 8 V. The device also functions as a self-powered sensor to monitor snowfall, depth of accumulation, wind direction and speed in snow or ice environments.
Snow-TENG: (a) use and detection of biomechanical movements by joining a snow-TENG to different locations of the human body; (b) measuring the electrical output of a snow TENG device using a snow mode when connected to (i) shoulder, (ii) wrist and (iii) knee; (c-i) a photograph of the snow-badembled TENG device attached to the bottom of a snow boot as a self-powered biomechanical sensor; (c-ii) electric snowshoes-TENG when the user makes different movements: running, jumping, walking and walking. Image credit: Ahmed et al, doi: 10.1016 / j.nanoen.2019.03.032.
The snow-TENG is small, thin and flexible like a sheet of plastic, and generates charge through static electricity.
"Static electricity is produced from the interaction of a material that captures electrons and another that abandons electrons. You separate the charges and create electricity from practically nothing, "said lead author Professor Richard Kaner of the University of California at Los Angeles and Tanta University, Egypt.
The snow is positively charged and abandons the electrons. Silicone, a material similar to synthetic rubber that is composed of silicon atoms and oxygen atoms, combined with carbon, hydrogen and other elements, is negatively charged. When the snow falls in contact with the surface of the silicone, it produces a charge that the device captures, creating electricity.
"The snow is already loaded, so we thought, why not bring another material with the opposite charge and extract the charge to generate electricity?" Said co-author Dr. Maher El-Kady, a researcher at the University of California at Los Angeles. Angels
"While snow likes to give up electrons, the performance of the device depends on the efficiency of the other material to extract these electrons. After testing a lot of materials, including aluminum and Teflon sheets, we found that silicone produces more load than any other material. "
"About 30% of the Earth's surface is covered with snow every winter, during which solar panels often do not work," he said.
"The accumulation of snow reduces the amount of sunlight that reaches the solar array, which limits the output power of the panels and makes them less effective."
"The new device could be integrated into solar panels to provide a continuous power source when it snows."
The snow-TENG can be used to monitor winter sports, such as skiing, to more accurately badess and improve an athlete's performance when running, walking or jumping. It also has the potential to identify the main movement patterns used in cross-country skiing, which can not be detected with a smart watch.
The device could give way to a new generation of self-powered portable devices to track athletes and their performances. You can also send signals, which indicate whether a person is moving. It can indicate when a person is walking, running, jumping or marching.
The researchers used 3D printing to design the device, which has a silicone layer and an electrode to capture the charge.
"We believe that the device could be produced at low cost given the ease of manufacture and the availability of silicone," said Professor Kaner.
Abdelsalam Ahmed et al. 2019. All the printable triboelectric nanogenerator based on snow. Nano energy 60: 17-25; doi: 10.1016 / j.nanoen.2019.03.032