Scientists at the University of Massachusetts Amherst (UMass) have invented a new way to make electricity. Their method uses super-tiny holes to make electricity from moisture in the air. The scientists hope the method will one day lead to cheap, clean electricity anywhere at any time.
Nanotechnology
Nanotechnology, or nanotech, is a scientific area that deals with making or changing things that are incredibly tiny. We’re used to measuring things using sizes like a meter (a little more than a yard). But nanotech is measured in nanometers – one billionth of a meter (0.000000001 meter). That’s extremely tiny.
Humidity, or moisture in the air, is what helps create the electricity. Water droplets in the air carry an electric charge. In clouds, these water droplets build up large charges, which we later see as lightning.
(Source: Jun Yao, via UMass.)
One of the researchers, Jun Yao, described the new invention as a “small-scale, man-made cloud”. Since the new device generates electricity from the air, the scientists call it “Air-gen”.
The new device is very small and very simple. In it, water molecules from the air move through tiny holes from the upper part of a material down into the lower part of the material.
The holes are the key. The material has lots of of teeny-tiny holes called “nanopores”. These nanopores are 100 nanometers across. That’s about 1,000 times thinner than the width of a human hair.
As the water molecules work their way through the nanopores, they upset the electrical balance between the upper and lower parts of the material, leaving the upper part with a greater charge. This “imbalance” between the two parts is what creates the electricity.
(Source: Liu et al., 10.1002/adma.202300748, via UMass.)
Using two electrodes – one above the material and one below – the scientists were able to take the electricity and use it, as if the Air-gen were a battery. Currently, the device only makes a small amount of electricity – enough to power a small sensor. But in lab tests, the Air-gen, which is a little bigger than a fingernail, produced that electricity all day and all night for a week, powered by nothing but the air.
Scientists have tried to make electricity from humidity before, but those methods didn’t work for long, or were expensive to make. But in 2020, Dr. Yao and his team found a way of getting electricity from humidity using special “nanowires” made from bacteria.
In time, that research led the scientists to the key discovery of the Air-gen: almost any material can create electricity in this way as long as it has nanopores of the right size. This is important because it means in the future, the devices can be made very cheaply.
(Source: Derek Lovley/Ella Maru Studio, via UMass.)
The researchers are hopeful that the Air-gen will become an important green energy source.
Many scientists are impressed with the ideas behind the Air-gen. But some scientists have suggested that it might be hard for the Air-gen to create enough electricity to really make a difference – especially compared to power sources like solar energy.
But Dr. Yao and his team are already working on ways to make Air-gen technology more powerful. Because the device is so thin, the scientists believe that many, many Air-gen layers could be stacked on top of each other to create more electricity without taking up more space.
Dr. Yao says, “What I envision [imagine] is that sometime in the future, we can get clean electricity wherever we go.”
Did You Know…?
The Air-gen works better when there’s more humidity, but it can even work in areas as dry as the Sahara Desert.