Scientists managed to build a device that generates electricity from the air, using just a pair of electrodes and a material full of small holes, less than 100 nanometers in diameter. Utilizing the moisture in the air and collecting the charge that the hovering liquid provides, and working in any climate, the technology holds promise for a future full of clean, practical energy.
Is there electricity in the air?
Yes there is! In fact, every water molecule carries some charge with it. The tiny holes in the film are small enough to let water through, generating electricity from the accumulation of molecules. It is an imitation of the process by which clouds generate the electricity discharged in lightning.
Humidity is always in the air, regardless of the percentage we check in the weather. Because of this, the technology works in any weather condition, already gaining an advantage over other “less reliable” systems, such as solar energy and wind energy, since they depend on the sun or wind to work efficiently.
Knowing clouds and lightning at a scientific level, it’s common to wonder why we don’t take advantage of this energy – with the answer lying in the difficulty of capturing such high charges and, above all, storing them so quickly. Jun Yao and his team of scientists at the University of Massachusetts Amherst then came up with the idea of building their own replica of the natural world.
Previously, scientists had built a device that uses a protein derived from bacteria to generate electricity from moisture in the air. From this they realized that it is possible to use many other materials for the same purpose, as long as the holes made in them are small enough. This type of device, which the team calls an “Air-gen,” can be made from a range of organic, inorganic, and biological materials—almost anything that exists, in fact.
The science of power generation
Air molecules travel about 100 nanometers—each measurement is less than a millionth the width of a human hair—until they bump into each other. When water travels through a thin material filled with tiny holes, electrical charge tends to build up on top of the material.
As fewer molecules reach the bottom, a charge imbalance is generated, as in a cloud. Electrodes on either side then deliver electricity to whatever device needs power. This becomes a moisture-powered battery, an excellent source of renewable and widely available energy.
As the material used is extremely thin, it can be stacked by the thousands and can generate several kilowatts of energy. Now, it will be necessary to scale the invention so that it works both with small devices – such as wearables, such as smartwatches – and for an entire house, generating enough electricity to power all your appliances.
For that to be possible, Yao’s team still has to figure out how to collect electricity from a large surface area and how best to stack sheets of material vertically, improving the device’s output without using up extra space. The initiative is among many others, such as the one that intends to generate energy from human heat, the one that seeks to generate energy in the shadows and the one that wants to filter water and generate energy from the same device.
Source: Advanced Materials
