You’ve seen the cartoons of engines powered by hamster wheel. Well, University of Michigan engineers led by Ethem Aktakka are designing motors that use green June beetle (Cotinis nitida) power. Specifically, they converted the kinetic energy of wing flapping into electricity. Each beetle can generate up to 115 µW of power, enough to power tiny sensors or cameras carried by the insect.
A piezoelectric beam attached to a Green June Beetle reveals the optimum location to scavenge energy and shows that up to 115 µW total power can be generated from the insect’s body movements.
The beetles used for these tests were all tethered. The researchers attached piezoelectric beams to various parts of the insects’ bodies to see which configurations generated the most power. Of course, the point isn't to attach insects to treadmills for energy production. Eventually, the beetles would be free flying, taking their sensing payloads into small or dangerous spaces.
You may be wondering, as I was, how you persuade a beetle to investigate the exact locations you need visited. As you can see in the video below, it turns out that insects can be controlled rather handily by the application of a few implanted electrodes.
In fact, it turns out that it’s easier to manipulate a living insect into doing what you want than to build a robot to do the same thing. The green June beetles in this study were not asked for their commentary on this point.