Researchers have recently developed a new metasurface-based antenna, which represents a substantial step toward the goal of harvesting energy from radio waves. With this technology, users can provide wireless power to sensors, LEDs, and other simple devices with low energy requirements through the radio waves currently used by Wi-Fi, Bluetooth transmission, etc.
"By eliminating wired connections and batteries, these antennas can help reduce costs, improve reliability, and make some electrical systems more efficient," said research team leader Jiangfeng Zhou from the University of South Florida. "This will help Powering smart home sensors, such as those for temperature, lighting, and motion, or for monitoring the structure of buildings or bridges, where changing batteries may be difficult or impossible."
The research results were recently published in Optical Materials Express.
The researchers report that lab tests of their new antenna show that it can harvest 100 microwatts of power from low-power radio waves, enough to power a simple device. This is possible because the metamaterial used to make the antenna exhibits perfect absorption of radio waves and is designed to work at low intensities.
"While more work is needed to miniaturize the antenna, our device uses ambient power levels found in the real world at high The efficiency crosses the critical threshold of 100 microwatts of harvested power. The technology can also be tuned so that it can provide a source of radio waves to power or charge devices around the room."
Scientists have been trying to harvest energy from radio waves for quite some time, but have struggled to get enough energy to function. This situation is changing, thanks to the development of metamaterials and the ever-increasing ambient sources of available radio frequency energy, such as cell phone networks, Wi-Fi, GPS and Bluetooth signals.
Zhou said: "With the huge explosion of radio wave-based technologies, there will be a large amount of waste electromagnetic radiation that can be collected. This, coupled with advances in metamaterials, creates a ripe environment for new devices and applications, These devices and applications can benefit from capturing this waste energy and putting it to use."
