New device only generates energy from air

In 2020, scientists from the University of Massachusetts at Amherst fabricated a nanowire from the bacterium Geobacter sulfurreducens. And they showed that with its help it is possible to constantly generate electricity from air in which there is at least a small amount of moisture. The whole system worked on the chemistry of the bacteria and the pores in the film that covered them. After continuing these studies, the scientists discovered that the type of nanowire was not necessary to achieve the desired result. The main thing is the size of the pores in the film.

How does it work

Almost any material has the ability to draw electricity from the air, if it has a certain property. This property is the mean free path of a particle before colliding with another particle. For water molecules, it is equal to 100 nanometers.

The new device consists of two layers of nanofilm. The top one has holes with a diameter of less than 100 nanometers. They act as a sieve, trapping and holding water molecules on the surface. When they accumulate in the upper layer, they create a natural electric charge that is higher than the charge on the lower layer of the film. This imbalance between the two layers creates an electric current like a lightning discharge.

The idea is very simple, but no one has discovered it until now, and it opens up so many possibilities. The generator can be made from literally any material, providing a wide variety of inexpensive and environmentally friendly products. You can imagine one such generator is made for tropical forests and another for arid regions.
– says team leader Yun Yao.

It is not clear in what volumes the energy is produced and to what extent the technology can be scaled. It is also unclear whether it will be used to power small devices such as watches, bracelets, headphones. Ultimately, the method requires constant access of moisture to the nanofilm.