These spiral generators scavenge power when the beetle beats its wings.
What's the News: Building tiny fly-like robots---for spying, search and rescue, and so on---has a long history in robotics. But some researchers, citing the challenge of building agile, dynamic machines at that scale, have turned to Mother Nature instead and made living beetles into cyborgs
, controlling their flight via neural implants. Finding a power source that's light enough for these beetles to port around has been difficult, but now, a team of roboticists have found that harvesting power from their beating wings
could be a way to make these 'borgs go battery-less. How the Heck:
The researchers mounted piezolectric generators, which produce power when they're bent or compressed, on the thoraxes of green june beetles near where the wings attach.
Trying out two different shapes, spiral and beam-like, with two different designs each, they were able to harvest about 45 µW of power from each beetle, and demonstrated that the closer they got to the base of the beetles' wings, the more they could scavenge. Right near the base, they could increase their power output to 115 µW.
They estimate that if the generator can be hooked up directly to the beetle's wing, though, they could increase power output by 10 times, enough to run the flight-control neural implants.
What's the Context:
This isn't the first time scientists have tried to harvest energy from an insect's own body. Previous attempts have focused on skimming thermal energy from the insect's body heat or using a resonant magnetic device to scavenge energy from vibration.
The piezolectric approach has the potential to harvest more energy than the body heat version and be more reliable than the vibration option, whose output fluctuated during even minute changes in the beetle's wingbeat frequency.
Not So Fast:
The researchers haven't yet attached the generator directly to the wing to achieve that 10-fold boost, which will be required before they can try it out on beetles with neural implants.
The Future Holds: Fabricating these tiny generators is still a difficult process, so the team is working on developing more standardized techniques. Reference: Ethem Erkan Aktakka, et al. “Energy scavenging from insect flight.” J. Micromech. Microeng. 21 (2011) 095016 (11pp) DOI:10.1088/0960-1317/21/9/095016
Image courtesy of Aktakka, et al. and J. Micromech. Microeng.