Researchers at the University of Massachusetts Amherst have created a
gadget that harnesses atmospheric moisture and a naturally occurring protein
to produce electricity. They believe this innovative technology might have a
big impact on renewable energy sources, climate change mitigation, and
medical advancements in the future.
According to a story published in Nature today, electrical engineer Jun Yao
and microbiologist Derek Lovley of UMass Amherst have developed an
air-powered generator, or "Air-gen," using protein nanowires that are
electrically conductive and made by the bacteria Geobacter. By attaching
electrodes to the protein nanowires in this manner, the Air-gen allows the
naturally occurring water vapor in the atmosphere to be converted into
electrical current.
Yao claims, "We are actually creating electricity out of thin air." "The
Air-gen produces clean energy continuously." As Lovely puts it, "It's the
most amazing and exciting application of protein nanowires yet." Lovely has
spent the last thirty years developing sustainable biology-based electronic
materials.
Yao's lab has created new technology that is inexpensive, renewable, and
non-polluting. It can produce electricity even in the Sahara Desert and
other regions with extremely little humidity. It offers a lot of advantages
over other renewable energy sources like solar and wind, according to
Lovley, because the Air-gen doesn't need wind or sunshine to function, and
"it even works indoors."
The researchers clarify that all that is needed for the Air-gen gadget is a
thin layer of protein nanowires that is less than 10 microns thick. An
electrode supports the bottom of the film, and an electrode covering a
smaller portion of the nanowire film is positioned on top. Water vapor from
the atmosphere is absorbed by the coating. The parameters that produce an
electrical current between the two electrodes are determined by the surface
chemistry and electrical conductivity of the protein nanowires as well as
the tiny holes that exist between the nanowires inside the film.
According to the researchers, tiny electronics can be powered by the
current generation of Air-gen devices, and they anticipate commercializing
the technology shortly. They want to build a compact Air-gen "patch" that
can power wearable electronics, such smart watches and health and fitness
monitors, in order to do away with the need for conventional batteries. In
order to do away with the need for frequent charging of cell phones, they
also want to produce Air-gens.
Yao states, "Building large-scale systems is the ultimate goal." The
technique may be used, for instance, in wall paint that powers your house.
Alternately, we may create independent air-powered generators that provide
electricity outside of the grid. I have no doubt that we will be able to
create massive systems that will significantly contribute to the production
of sustainable energy once wire production reaches an industrial
scale."
In an effort to further the useful biological potential of Geobacter,
Lovley's team created a novel microbial strain that can mass generate
protein nanowires more quickly and affordably. He claims that "we turned E.
coli into a protein nanowire factory." "Protein nanowire supply won't be a
bottleneck to developing these applications with this new scalable
process."
They claim that the Air-gen discovery is the result of an uncommon
multidisciplinary partnership. More than thirty years ago, Lovley found the
Geobacter bacteria in the Potomac River silt. Later, his group found that it
could create protein nanowires that were electrically conductive. Yao had
spent years working as an electrical device engineer at Harvard University
using silicon nanowires before moving to UMass Amherst. They teamed up to
investigate the possibility of creating practical electrical devices using
the protein nanowires extracted from Geobacter.
While working on sensor devices in Yao's lab, Ph.D. student Xiaomeng Liu
made an unexpected discovery. He remembers, "I saw that the gadgets created
a current when the nanowires were touched with electrodes in a particular
way. I discovered that water was adsorbed by protein nanowires, creating a
voltage gradient across the device, and that exposure to ambient humidity
was crucial."
Yao's lab has created several more uses for the protein nanowires in
addition to the Air-gen. Yao declared, "This is just the start of a new era
of protein-based electronic devices."
Provided by
University of Massachusetts Amherst
