A team of scientists at Columbia University designed a prototype engine that can solely rely on water and shape-changing bacterial spores to produce energy. The new engine, which currently costs only five bucks to produce, may represent a major advance in renewable energy research.
The spores that are the core of the new technology shrink and swell whenever there’s a certain change in the surrounding levels of humidity, researchers explained. They also said that the prototype was only the beginning since the technology held a huge potential.
The study on the new engine and its applications was published June 16 in the journal Nature Communications.
According to the developers, the experiments had been ongoing for nearly a decade. The lead author prof. Ozgur Sahin had the idea of using the bacterial spores to produce energy during a project involving a super-advanced microscope his team had developed.
The professor said that he learned from scientific literature that those spores shrank when the air was dry and expanded when the air become humid. But from his own studies he learned that the tiny life forms could also be very rigid. So, he concluded that there must be an energy output when spores changed shape.
The professor later found that indeed the spores could generate large amounts of energy during their expansion and contraction. His team managed to build a small engine with shutter-controlled humidity to see the spores in action.
This year, the team were able attach the bacterial spores on shutters and the engine became autonomous. Whenever the atmosphere became too dry, spores contracted and closed the shutters. But closing the shutters raised moisture, which forced spores to expand and open the shutters again which led to another cycle over and over again.
The mechanism is very similar to the steam engine, but it doesn’t need humans to maintain a controlled temperature. Researchers compared the shutters coated with spores with a muscle that expands and contracts by itself but in the meantime it releases energy.
During their experiments, Columbia University engineers used the ability of the spores to expand and contract to generate piston-like movements within experimental engines. The engines contained plastic strips enveloped in the bacterial spores to allow the team to have a proper control on the process.
At this moment, the engine is powerful enough to generate energy for small light bulbs. So, developers are thinking of providing energy for oil rigs or other devices that are located on the sea. As a follow-up, researchers plan to boost the energy output by finding a better glue to make the spores stick to the engine parts.
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