US researchers have developed a new device that uses a natural protein to create electricity from moisture in the air, an innovation that is non-polluting, renewable and low-cost.
Scientists at the University of Massachusetts (Umass) Amherst who worked in the project believe that the new technology could have significant implications for the future of renewable energy, climate change and in the future of medicine. Thay have called the device "Air-gen", or air-powered generator.
According to the researchers, Air-gen connects electrodes to the tiny protein wires in such a way that it generates electrical current from water vapour naturally present in the atmosphere. It is made using ultrasmall electrically conductive protein wires produced by the microbe Geobacter which was discovered in the mud of the Potomac River in the US more than 30 years ago.
"We are literally making electricity out of thin air. The Air-gen generates clean energy 24/7," said Jun Yao, study co-author from UMass Amherst.
They added that it can generate power even in areas with extremely low humidity such as the Sahara Desert.
Air-gen can source small electronics at the current level, but soon may be able to power electronic wearables such as health and fitness monitors and smart watches. They can be applied to smartphones to do away with periodic charging.
According to Derek Lovely, another co-author of the study from UMass Amherst, the device has significant advantages over other forms of renewable energy including solar and wind since "it even works indoors."
Air-gen requires only a thin film of tiny protein wires which are less than 10 micrometres thick and absorb water vapour from the atmosphere, the scientists said.
The bottom of the film, they added, rests on an electrode, while a smaller electrode that covers only part of the protein wire film sits on top.
With peculiar surface chemistry features, and the ability to conduct electricity, these tiny protein wires and the fine pores between them, establish conditions favourable for generating an electrical current between the two electrodes, the study noted.
The scientists hope to scale up the technology to power small electronics.
"The ultimate goal is to make large-scale systems. For example, the technology might be incorporated into wall paint that could help power your home. Or, we may develop stand-alone air-powered generators that supply electricity off the grid," Yao said.
"Once we get to an industrial scale for wire production, I fully expect that we can make large systems that will make a major contribution to sustainable energy production," he added.
The scientists recently engineered a new microbial strain to more rapidly and inexpensively mass produce the protein wires.
"We turned E. coli into a protein nanowire factory. With this new scalable process, protein nanowire supply will no longer be a bottleneck to developing these applications," Lovely said.
The study was published in Nature.
(With input from PTI)