'Air' Electricity Generating Device Developed
They found him more than 30 years ago, hidden on the muddy shores of the Potomac River. This interesting " precipitate " was doing things that were not seen before in bacteria.
This unusual microbe, belonging to the genus Geobakter , attracted attention with its ability to produce magnetite without oxygen. But scientists have found that over time,he could do other things, such as theelectrically conductive bacterial nanowire .
For years, researchers have been looking for ways to take advantage of this natural gift . With a device they call Air-gen, they may have finally done it. According to the team, this device can generate electricity almost from the air.
" We're literally producing electricity from the air," says Jun Yao, an electrical engineer at Massachusetts Amherst University . “Air-gen produces clean energy 24/7.”
This claim may sound like an exaggeration, but a new study by Yao and his team ; It describes how this generator, which gets its power from the air, generates electricity only from the air around it. Everything is possible thanks to the protein nanowires produced by Geobakter ( G. sulgurreducens ) that can conduct electricity.
Air-gen is only 7 micrometers thick and placed between two electrodes; but it also consists of a thin layer of protein-exposed nanowires.
The nanowire layer exposed to moisture is able to absorb water vapor in the atmosphere, and the device thus produces a continuous electric current transmitted between the two electrodes.
Research team; he says that the electric charge is probably due to the change in moisture that causes the protons to disperse in the nanowire material.
The authors of the study explain : “It is assumed that this charge distribution causes an electric field that compensates for the immobilized membrane potential in biological systems or provides a counterpart.”
“A moisture change that is fundamentally different from what is seen in previous systems and is maintained; It explains this voltage output that is constantly occurring on the nanowire device. ”
The discovery was almost accidental. While experimenting with Yao devices, he noticed that the devices transmit the electricity completely to themselves on sight.
"When nanowires made contact with the electrodes in a certain way, I saw the devices generate a current," says Yao . “I found that exposure to moisture in the atmosphere is necessary, and protein nanowires absorb water, producing a voltage change across the device.”
In previous studies , hydro-tensile strength has been produced using other types of nanomaterials (such as graphene) . But in these attempts, electricity that was mostly short-pulsed and lasted only seconds. ”
In contrast, the Air-gen produced a continuous voltage of about 0.5 volts and a current power of about 17 microamps per square centimeter. Although this amount is not much; The team says that by connecting multiple devices, small devices such as smartphones and other personal electronic devices can produce enough power to charge. Moreover, all this will be done without waste and without using anything other than ambient humidity (even in dry areas such as the Sahara Desert).
"The ultimate goal is to build large-scale systems," said Yao . in the future, using this technology, he explains that electricity can be supplied to homes by including nanowire in wall paint.
“When we reach an industrial scale for cable production, I hope we can build large systems that will make a major contribution to sustainable energy production.”
If there is an obstacle to making this seemingly incredible potential a reality, it is the limited amount of nanowires created by G. sulgurreducens .
A study by team member Derek Lovley on the subject could offer a solution to this problem (he was a microbiologist who first identified Geobakter microbes in the 1980s ). Genetic engineering on other bacteria, such as coli bacillus , can make it possible to supply huge amounts of nanowires.
“We transformed the bacillus bacterium into a protein nanowire factory,” says Lovley .
“With this new and scalable process, the protein nanowire supply will no longer be a bottleneck in the development of these applications.”
The findings were presented in the Nature bulletin.
Author: Peter Dockrill / ScienceAlert.