Renewable device uses bacteria to harness electricity ‘out of thin air’

18 Feb 2020

Image: © Aamon/

A new type of renewable energy device has been forged from bacteria and can create electricity just from moisture in the air.

A new device could one day join the established renewable energy technologies such as wind and solar, but won’t be reliant on the weather. Scientists at the University of Massachusetts Amherst published findings on this device to Nature, saying it uses natural protein to create electricity from moisture in the air.

If the device achieves its potential, they added, it could have significant implications for the future of renewable energy, the climate crisis and medicine. The device, named Air-gen, contains electrically conductive protein nanowires produced by the microbe Geobacter.

Air-gen connects electrodes to protein nanowires in such a way that electrical current is generated from the water vapour naturally present in the atmosphere.

“We are literally making electricity out of thin air,” said engineer Jun Yao, who created the device with microbiologist Derek Lovely. “The Air-gen generates clean energy 24/7.”

Working in the device’s favour is that it is non-polluting, renewable, low-cost and flexible. The researchers said that it can work in areas with extremely low humidity such as the Sahara Desert, doesn’t require sunlight or wind and can also work indoors.

Illustration of green protein nanowires generating electricity from air moisture.

Graphic image of a thin film of protein nanowires generating electricity from atmospheric humidity. Image: UMass Amherst/Yao and Lovely Labs

Scaling up

All that’s required is a thin film of protein nanowires less than 10 microns thick, with the bottom of the film resting on an electrode. Meanwhile, a smaller electrode that covers only part of the nanowire film sits on top.

The film absorbs water vapour from the atmosphere and starts generating electricity using a combination of electrical conductivity, surface chemistry of protein nanowires and fine pores between nanowires in the film.

The current generation of Air-gen can power small electronics, with expectations that the invention could be ready for commercial-scale applications soon. The researchers’ plan is to develop a smaller Air-gen ‘patch’ that can power devices such as wearables, eliminating the need for batteries.

“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,” said Jun.

“Or, we may develop standalone air-powered generators that supply electricity off the grid. 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.”

Colm Gorey was a senior journalist with Silicon Republic