Soon We Will Charge Our Phones Through Wi-Fi, As Per MIT Physicist's Invention

With the present technology, humans are able to harness only some forms of energy. A range of energy forms are yet untapped and one such are the electromagnetic waves with a frequency between microwaves and infrared light. These electromagnetic waves are known as ¡®Terahertz waves¡¯ or ¡®T-rays¡¯ and are emitted by any device that sends out a Wi-Fi signal.

So what if humans design a way to harness these waves? That would essentially mean a viable power source coming right out of your existing Wi-Fi router. A genius practical implication then would be to charge your devices straight through the Wi-Fi.

Physicists at MIT have come up with a blueprint for a device that does exactly that. Liang Fu and Su-yang Xu have developed a device that is anticipated to convert ambient terahertz waves into a direct current, a form of electricity that powers household electronics in our every day lives.

Based on quantum mechanics, the physicists plan to combine graphene with boron nitride within the device. The electrons in graphene would then flow in a common direction as the incoming terahertz waves should help in shuttling the graphene¡¯s electrons to unidirectional flow through the material, thus forming a direct current.

(Representative Image: Reuters)

The theory is quite different from the regular experiments directed at harnessing the T-rays, which mostly worked at ultra-cold temperatures deeming them impractical in daily lives. Instead of taking the common approach to the challenge, Isobe tried to find a solution at an atomic level. That solution was to check if a material¡¯s own electrons could be induced to flow in one direction, thus using the incoming terahertz waves to form a DC current.

There were some challenges with the concept though. First, Isobe had to find a material free of impurities that might hinder the unidirectional flow of the electrons. He found Graphene to be the ideal material for this reason.

Also, the concept needed Graphene¡¯s inherent symmetry or ¡®inversion¡¯ to be broken, that makes the electrons move in all directions upon an incoming energy. This challenge was met by placing the Graphene upon a layer of Boron Nitride that propelled ¡®skew scattering¡¯ among the electrons due to the differential pull of Boron and Nitrogen on the electrons. Clouds of electrons start flowing in a particular direction in such an arrangement.

Post the application of this knowledge, the physicists were able to observe DC current forming through the incoming terahertz waves. They, however, also observed that the amount of DC current formed was directly proportional to the strength of Terahertz waves.

(Representative Image: Reuters)

So they decided to amplify this strength by concentrating the waves within the device. The researchers came up with a blueprint for a terahertz rectifier made up of a small square of graphene that sits atop a layer of boron nitride and is sandwiched inside an antenna that would collect and concentrate ambient terahertz radiation. The concentrated waves would then come in as a boosted signal, enough to form a DC current.

The researchers are now working with experimental physicists at MIT to develop a physical device out of their design. They have published their results in the journal Science Advances, and have also filed a patent for the new ¡°high-frequency rectification¡± design.

If and when developed, such a device would be able to charge household electronics straight through the Wi-Fi signals. In fact, an even more important implication would involve wirelessly powering implants in a patient¡¯s body, without requiring surgery to change an implant¡¯s batteries. Unthinkable, right? But not impossible it seems!

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