Scientists have created amazing things. Almost anything can be used to create a device that continuously emits energy from wet air.
It’s not a ready-to-use development, but it does, its developers say, go beyond the limitations of other harvesters. All requirements must be filled with nanopores less than 100 nanometers in diameter. That’s around one thousandth of the width of a human hair, so easier said than done but easier than expected.
Such materials can harvest electricity produced by invisible water droplets in moist air, according to a team led by engineer Xiaomeng Liu of the University of Massachusetts Amherst.
He called what he found the “generic Air-gen effect”.
“Air has a lot of electricity,” said engineer Jun Yao of UMass Amherst.
“Think about a cloud, which is nothing but a mass of water droplets. Each of these droplets has a charge, and if the conditions are right, the cloud can produce lightning – but we don’t know how to reliably harness electricity from lightning. What we have done is create a cloud of lightning. a human-made energy source that provides us with predictable and continuous electricity so that we can harvest.”
If Air-gen sounds good, it’s because the group previously planned air energy harvesting. However, their original device relied on proteins called nanowires produced by a bacterium Geobacter sulphureducens.
Well, as it turns out, bacteria aren’t important.
“What we realized when we made it Geobacter The discovery is that the ability to generate electricity from the air – what we called the ‘Air-gen effect’ – is simple: any kind of reality can harvest electricity from the air, as long as it has certain properties,” Yao explains.
The material is nanopores, and their size depends on the free passage of water molecules in the humid atmosphere. It is the distance that a water molecule can travel in space before it collides with another water molecule.
The generic Air-gen device is made from a thin film of materials, such as pads, silicon dioxide, or graphene oxide. Water molecules in the atmosphere can easily enter the nanopores and move from the top of the film to the bottom, but they run into the side of the pore as they move.
This transfer of charge to the material, creates a bond, and because many water molecules go to the surface of the film, a negative charge occurs between the two sides.
This creates an effect similar to what we see in lightning clouds: the rising air causes more collisions between the water droplets at the top of the cloud, making the clouds more dense and less dense.
In this case, the charge can be sent to use small appliances or stored in a battery of some kind.
Right now, it’s still in the early stages. The cellulose film that the team tested had a voltage of 260 millivolts in the ambient environment, while a cell phone requires a voltage of about 5 volts. But the film’s thinness means it can be stored to add Air-gen components to make it work.
And the fact that they can be made from a variety of materials means that the devices can be adapted to the environment in which they are to be used, the researchers say.
“The concept is simple, but it’s unprecedented, and it opens up all kinds of possibilities,” says Yao. “You can compare the harvesters that are made with one type of product in the forest areas, and another in the dry areas.”
The next step would be to test the equipment in different locations and try to improve it. But the results of generic Air-gen are real, and the opportunities they represent are promising.
“This is very exciting,” says Liu. “We’re opening the door to harvesting good electricity from thin air.”
Research has been published in Advanced Equipment.