TriboElectricity, The Green Energy Source

Researchers from Clemson’s Nanomaterials Institute (CNI) are one step closer to wirelessly powering the world using triboelectricity, a green energy source. In March 2017, a group of physicists at CNI invented the ultra-simple triboelectric nanogenerator or U-TENG, a small device made of plastic and tape that generates electricity from motion and vibrations. When the two materials are brought together — through such actions as clapping the hands or tapping feet — they generate voltage that is detected by a wired, external circuit. Electrical energy, by way of the circuit, is then stored in a capacitor or a battery until it’s needed.

Nine months later, in a paper published in the journal Advanced Energy Materials, the researchers reported that they had created a wireless TENG, called the W-TENG, which greatly expands the applications of the technology. The W-TENG was engineered under the same premise as the U-TENG using materials that are so opposite in their affinity for electrons that they generate a voltage when brought in contact with each other.

In the W-TENG, plastic was swapped for a multipart fiber made of graphene — a single layer of graphite, or pencil lead — and a biodegradable polymer known as polylactic acid (PLA). PLA on its own is great for separating positive and negative charges, but not so great at conducting electricity, which is why the researchers paired it with graphene. Kapton tape, the electron-grabbing material of the U-TENG, was replaced with Teflon, a compound known for coating nonstick cooking pans.

After assembling the graphene-PLA fiber, the researchers pulled it into a 3-D printer and the W-TENG was born. The end result is a device that generates a maximum of 3,000 volts — enough to power 25 standard electrical outlets or, on a grander scale, smart-tinted windows or a liquid crystal display (LCD) monitor. Because the voltage is so high, the W-TENG generates an electric field around itself that can be sensed wirelessly. Its electrical energy, too, can be stored wirelessly in capacitors and batteries.

It cannot only give you energy, but you can use the electric field also as an actuated remote. For example, you can tap the W-TENG and use its electric field as a ‘button’ to open your garage door, or you could activate a security system — all without a battery, passively and wirelessly,” said Sai Sunil Mallineni, the first author of the study and a Ph.D. student in physics and astronomy.

Source: http://newsstand.clemson.edu
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