A team of scientists from Oxford University has demonstrated how the natural movement of bacteria could be harnessed to assemble and power microscopic windfarms.
The study, which has been published in the journal Science Advances, used computer simulations to demonstrate that the chaotic-swarming effect of bacteria could be organised to turn cylindrical rotors and offer a steady source of power.
Researchers Oxford University Department of Physics and co-authors of the study, Tyler Shendruk and Amin Doostmohammadi noted that these biologically driven power plants could someday be used for powering tiny, microscopic man-made machines that are self-assembled and self-powered.
Shendruk said: “Many of society's energy challenges are on the gigawatt scale, but some are downright microscopic. One potential way to generate tiny amounts of power for micromachines might be to harvest it directly from biological systems such as bacteria suspensions.”
Dense bacterial suspensions are examples of active fluids that flow spontaneously. Swimming bacteria are capable of swarming and driving disorganised living flows, but most of the time, they are too disordered to extract any useful power.
But, when the team immersed a structure consisting of 64 symmetric microrotors, into this active fluid, it was found that the bacteria organised itself spontaneously such that neighbouring rotors began to spin in opposite directions. This structure was similar to a microscopic windfarm.
Shendruk added: 'The amazing thing is that we didn’t have to pre-design microscopic gear-shaped turbines. The rotors just self-assembled into a sort of bacterial windfarm.
The team said that when a single rotor was introduced into bacterial turbulence, it just got kicked around randomly. But, when an array of rotors was introduced, the bacteria suddenly formed a regular pattern, where neighbouring rotors started spinning in opposite directions.
Amin Doostmohammadi said: 'The ability to get even a tiny amount of mechanical work from these biological systems is valuable because they do not need an input power and use internal biochemical processes to move around.
Oxford University Department of Physics senior author Professor Julia Yeomans added: 'Nature is brilliant at creating tiny engines, and there is enormous potential if we can understand how to exploit similar designs.'
Image: Scientists at Oxford simulate bacteria-powered windfarm. Photo: Courtesy of University of Oxford.