How scientists turned humid air into renewable energy by accident

Sometimes the best experiments come out of pure luck.
Loukia Papadopoulos
Representational image of electricity.jpg
Representational image of electricity.

Валентин Игнаткин/iStock 

Last May, researchers at the University of Massachusetts (UMass) Amherst revealed they had managed to successfully generate a small but continuous electric current from humidity in the air. Now, a report by The Guardian is revealing the breakthrough came by surprise.

“To be frank, it was an accident,” told the news outlet 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 device, which was made from an array of microscopic tubes, or nanowires, was producing an electrical signal regardless.

The nanowires were bumping around inside the tube resulting in a small charge, and as the frequency of bumps rose, one end of the tube became differently charged from the other.

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

Yao’s team conducted a new study that saw their experiments move on from nanowires, and instead use materials with millions of tiny holes, or nanopores. The result is a device the size of a thumbnail that can generate roughly one microwatt.

“The beauty is that the air is everywhere,” added Yao. “Even though a thin sheet of the device gives out a very tiny amount of electricity or power, in principle, we can stack multiple layers in vertical space to increase the power.”

A miracle in action

Now, other scientists are saying that these devices do have the potential of producing the miracle of generating electricity from thin air. Peter Dobson, emeritus professor of engineering science at Oxford University, told The Guardian the experiments are proving fruitful.

“When I first heard about it, I thought: ‘Oh yes, another one of those.’ But no, it’s got legs, this one has,” said Dobson. “If you can engineer and scale it, and avoid the thing getting contaminated by atmospheric microbes, it should work.”

Others however say we still have a long way to go before these types of devices are powering our homes.

“How do these devices get manufactured?” told The Guardian Anna Korre, professor of environmental engineering at Imperial College London. “Sourcing raw materials, costing, assessing the environmental footprint, and scaling them up for implementation takes time and conviction.”

But this hasn’t stopped Yao from dreaming big.

“Lots of energy is stored in water molecules in the air,” he concluded to The Guardian. “That’s where we get the lightning effect during a thunderstorm. The existence of this type of energy isn’t in doubt. It’s about how we collect it.”