Energy-Harvesting Design Aims To Turn Wi-Fi Signals Into Usable Power
Arthur T Knackerbracket has found the following story:
Any device that sends out a Wi-Fi signal also emits terahertz waves -electromagnetic waves with a frequency somewhere between microwaves and infrared light. These high-frequency radiation waves, known as "T-rays," are also produced by almost anything that registers a temperature, including our own bodies and the inanimate objects around us.
Terahertz waves are pervasive in our daily lives, and if harnessed, their concentrated power could potentially serve as an alternate energy source. Imagine, for instance, a cellphone add-on that passively soaks up ambient T-rays and uses their energy to charge your phone. However, to date, terahertz waves are wasted energy, as there has been no practical way to capture and convert them into any usable form.
Now physicists at MIT have come up with a blueprint for a device they believe would be able to convert ambient terahertz waves into a direct current, a form of electricity that powers many household electronics.
Their design takes advantage of the quantum mechanical, or atomic behavior of the carbon material graphene. They found that by combining graphene with another material, in this case, boron nitride, the electrons in graphene should skew their motion toward a common direction. Any incoming terahertz waves should "shuttle" graphene's electrons, like so many tiny air traffic controllers, to flow through the material in a single direction, as a direct current.
The researchers have published their results today in the journal Science Advances, and are working with experimentalists to turn their design into a physical device.
[...] The team has filed a patent for the new "high-frequency rectification" design, and the researchers are working with experimental physicists at MIT to develop a physical device based on their design, which should be able to work at room temperature, versus the ultracold temperatures required for previous terahertz rectifiers and detectors.
"If a device works at room temperature, we can use it for many portable applications," Isobe says.
He envisions that, in the near future, terahertz rectifiers may be used, for instance, to wirelessly power implants in a patient's body, without requiring surgery to change an implant's batteries. Such devices could also convert ambient Wi-Fi signals to charge up personal electronics such as laptops and cellphones.
"We are taking a quantum material with some asymmetry at the atomic scale, that can now be utilized, which opens up a lot of possibilities," Fu says.
Journal Reference: Hiroki Isobe et al. High-frequency rectification via chiral Bloch electrons, Science Advances (2020). DOI: 10.1126/sciadv.aay2497
Read more of this story at SoylentNews.