In our previous post we wrote about storing and harvesting energy in the air, and how Jun Yao discovered the potential. He has made more progress since he published his initial paper in 2020. His earlier work detailed how tiny protein wires harvested micro electricity from water molecules in the atmosphere. More work has followed, suggesting taking electricity from air in a laboratory is feasible.
The Theory Behind Taking Electricity from Air
Jun Yao explained the principles to Chris Baraniuk, for BBC Future Now on July 11, 2023. Most water molecules stayed near the surface of the nano wires, he noted, but a few penetrated more deeply. This separation “created a difference in charge between the upper and lower parts of the material layer”.
“Over time, you see that there is charge separation happening,” Yao continued. “That’s actually what happens in a cloud.” On a much larger and more dramatic scale, Chris Baraniuk adds, storm clouds also create a build-up of opposing electrical charges. That eventually discharges in the form of lightning.
It follows, therefore, that we could harvest electricity from air by influencing the movement of water molecules, Yao believes. That’s because this would in turn create just the right conditions for charge separation, enabling us to generate electricity. “The device can work literally anywhere on Earth,” he claimed back in 2020.
More Water Flows Under the Bridge Since Then
Yao and his colleagues published a follow-up report, which formed the basis for Baraniuk’s breaking news article. They had moved on from focusing on tiny protein nanowires produced by a bacterium. In fact, they had created nano pores in a variety of materials including graphene oxide flakes, polymers, and cellulose nanofibers derived from wood.
This suggests the structure of the material is the key, and not the material itself. Devices thinner than a human hair may have only generated fractions of volts, but Yao is not perturbed by this apparent limitation to electricity from air.
It simply suggests, he told Baraniuk, “that by using more material, or linking pieces of it together, you could begin to get useful charges of multiple volts.” Why you could even spray a liquid onto a surface, and provide an instant power source.
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