Vapour Ware? Hot air? Humid Air? ... or Electricity ?

[RTH10260]

‘It was an accident’: the scientists who have turned humid air into renewable power
Tesla speculated electricity from thin air was possible – now the question is whether it will be possible to harness it on the scale needed to power our homes

Ned Carter Miles
Sun 2 Jul 2023 11.00 BST

In the early 20th century, Serbian inventor Nikola Tesla dreamed of pulling limitless free electricity from the air around us. Ever ambitious, Tesla was thinking on a vast scale, effectively looking at the Earth and upper atmosphere as two ends of an enormous battery. Needless to say, his dreams were never realised, but the promise of air-derived electricity – hygroelectricity – is now capturing researchers’ imaginations again. The difference: they’re not thinking big, but very, very small.

In May, a team at the University of Massachusetts (UMass) Amherst published a paper declaring they had successfully generated a small but continuous electric current from humidity in the air. It’s a claim that will probably raise a few eyebrows, and when the team made the discovery that inspired this new research in 2018, it did.

“To be frank, it was an accident,” says the study’s lead author, Prof Jun Yao. “We were actually interested in making a simple sensor for humidity in the air. But for whatever reason, the student who was working on that forgot to plug in the power.”

The UMass Amherst team were surprised to find that the device, which comprised an array of microscopic tubes, or nanowires, was producing an electrical signal regardless.

Each nanowire was less than one-thousandth the diameter of a human hair, wide enough that an airborne water molecule could enter, but so narrow it would bump around inside the tube. Each bump, the team realised, lent the material a small charge, and as the frequency of bumps increased, one end of the tube became differently charged from the other.

“So it’s really like a battery,” says Yao. “You have a positive pull and a negative pull, and when you connect them the charge is going to flow.”

For their recent study, Yao’s team have moved on from nanowires, and instead are punching materials with millions of tiny holes, or nanopores. The device they have come up with is the size of a thumbnail, one-fifth the width of a human hair, and capable of generating roughly one microwatt – enough to light a single pixel on a large LED screen.



https://www.theguardian.com/science/202 ... able-power

[Patagoniagirl]

Wow. I love this stuff!

[tek]

My Alma Mater!
(My department too, at least partially)