By Stuart Layt
Australian researchers have discovered a substance that converts air into electricity, opening the way for future devices to be powered by the air around them.
Scientists from Monash University discovered that an enzyme produced by a common bacterium found in soil naturally converts hydrogen in the air into electricity.
Monash PhD candidate Ashleigh Kropp and Dr Rhys Grinter in the lab.Credit: Monash University
Many bacteria use hydrogen from the environment to generate power, but this enzyme – called Huc from the bacterium Mycobacterium smegmatis – does it in a unique way and is much more stable than others when isolated.
The research’s lead author, Dr Rhys Grinter from the Monash University Biomedicine Discovery Institute in Melbourne, said they had done a number of experiments to show Huc was generating power from air.
“It can turn hydrogen in the air into an electrical current that we can measure and that can power a small electrical circuit,” he said.
“We have only done this in a lab setting so far, but we’re confident that once it’s scaled up, it will be able to power a range of devices.”
Bacterial cultivation in the lab. The enzyme is isolated from the bacteria for use in experiments.Credit: Monash University
While Huc could not generate electricity at the level of a power plant, it could be used to power smaller devices, such as watches and smartphones.
Australia is positioning itself as a major player in the future of the hydrogen industry, with a stated goal of being a global hydrogen leader by 2030.
When Huc is isolated it is a clear liquid, which the researchers coat on electrodes to test its power-generating potential.Credit: Monash University
The research has shown that Huc can generate even more power when extra hydrogen is added, meaning it is well-placed to become part of the hydrogen takeup.
Monash PhD candidate and research co-author Ashleigh Kropp said the discovery was ideal for creating small fuel cells that could replace batteries for everyday devices.
The key difference between existing batteries and those that used Huc was that the latter could continue drawing power from the air theoretically indefinitely.
“Because it draws power from the air around it, it can continue running, and we know the protein is really stable – we can freeze it to minus-80C and heat it to 80C and it still functions,” she said.
“We haven’t yet tested just how long it will keep putting out power, but we want to explore that further.”
The researchers said it was also ideal for devices where a solar array would not be feasible, such as in underground sensors or implanted medical devices.
Grinter said it could be a decade before products using Huc-based fuel cells were viable, but added that the road to get there would be “hugely exciting”.
“The project reinforces the need for funding for basic science – the genesis of this project was simply to better understand how bacteria work in the environment,” he said.
“We’ve now isolated a molecular machine that has significant ramifications for power generation in the future.”
The research has been published in the journal Nature.
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