A new metamaterial-based antenna can harvest energy from radio waves, such as the ones used by mobile phone networks or Bluetooth connections.
Developed at the University of South Florida, technology based on the antenna could potentially provide wireless power to sensors, LEDs and other simple devices with low energy requirements.
“By eliminating wired connections and batteries, these antennas could help reduce costs, improve reliability and make some electrical systems more efficient,” said research team leader Jiangfeng Zhou.
“This would be useful for powering smart home sensors, such as those used for temperature, lighting and motion, or sensors used to monitor the structure of buildings or bridges, where replacing a battery might be difficult or impossible.”
Laboratory tests of the new antenna showed it can harvest 100 microwatts (μW) of power from low power radio waves, enough to power simple devices.
“This was possible because the metamaterial used to make the antenna exhibits perfect absorption of radio waves and was designed to work with low intensities,” a research announcement said.
“Although more work is needed to miniaturise the antenna, our device crosses a key threshold of 100μW of harvested power with high efficiency, using ambient power levels found in the real world,” said researcher Clayton Fowler. “The technology could also be adapted so that a radio wave source could be provided to power or charge devices around a room.”
Scientists have been trying to capture energy from radio waves for some time, but it has been difficult to obtain enough energy to be useful. This is changing thanks to the development of metamaterials and the ever-growing number of ambient sources of radio frequency energy available, such as mobile phone networks, Wi-Fi, GPS, and Bluetooth signals.
extract from Professional Engineering read more here