The chaotic movements of bacteria could be tamed to create electricity, powering miniature future gadgets, such as medical devices or other nanoscale machines.
A newly published paper from researchers at Oxford University explains how to turn a fluid soup of bacteria into a kind of miniature wind farm. The team dropped a minuscule array of 64 rotors into a microfluid, and something quite extraordinary happened. The bacteria, instead of milling about in all directions, organized themselves spontaneously into a regular flow. They moved between the rotors, causing them to spin in opposite directions, as you see in the illustration.
To imagine it on a larger scale, picture a room full of columns a few feet apart, and these columns can spin on their axes. Now imagine the room is crowded with people who are moving around. As they wander through, they are forced into a kind of organized flow in order to get anywhere. And as they move, they cause the column to spin. This spin, in the bacterial battery, could be used to generate electricity, just like a wind turbine.
The Oxford researchers’ breakthrough was the discovery that the rotors could be simple, symmetrical shapes. They didn’t need to be shaped like gears in order to "catch" the movement of the bacteria.
"Because these biological systems do not need an input power, rather using internal biochemical processes in order to encourage flow, it is extraordinarily valuable," says the Science News Journal.
The microscopic nature of the whole setup makes it perfect for powering tiny devices, such as injectable medical robots, but there are other possible uses too. The motion of the mini turbines is also ideal for mixing microfluids, like a teeny-tiny KitchenAid, and the direction of the controlled flow could also be harnessed.
The beauty of these bacterial batteries is that they’re self-powering, as long as the bacteria are kept alive. That’s not exactly perpetual motion, but in the right environment, where those bacteria are allowed to thrive, it might as well be.
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