Implanted Health Tech devices tend to be relatively large items such as pacemakers or stents in coronary arteries, but as smart devices continue to get smaller and smaller, microscopic implants could perform many useful tasks from sensing biometric data to providing therapeutic treatment. One of the big questions for such devices, however, is how to deliver power to them. Researchers are pursuing solutions ranging from radio waves to ultrasound, but what if these devices could contain an “engine” of their own to provide power as needed?

That’s the concept behind the work of a team of Oxford scientists. They have the idea that bacteria can provide the power needed to drive tiny implants. We don’t tend to think about it, because these organisms exist in such a tiny scale, but bacteria are equipped with structures that allow them to move around. The Oxford group found that they could create a matrix of tiny rotors. When immersed in a solution of swimming bacteria, the bacteria spontaneously organized themselves in such a way that caused the rotors to spin. Neighboring rotors spun in the opposite direction. As one of the researchers put it, “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.”

This effect could be harnessed to produce “persistent mechanical power” for tiny implant devices. This could be used to energize sensors, or drive tiny pumps to deliver medications in precise locations where they are needed. No batteries required.