Stanford University Researchers Create High-Speed Cyborg Jellyfish, Unlock Latent Performance Boost

Sea jellies fitted with a TinyLily microcontroller swim at 2.8 times their natural rate, but using only twice the energy.

Gareth Halfacree
2 months agoRobotics / Animals
A microcontroller is held in place with a wooden pin. (📷: Xu et al)

Researchers from Stanford University and Caltech have successfully created cyborg jellyfish which, in a twist to the usual case for such beasts, move faster and more efficiently than their natural brethren.

"Usually, co-opting the mobility system of an animal with electronics doesn’t improve things for the animal, because we’re not nearly as good at controlling animals as they are at controlling themselves," Evan Ackerman writes for IEEE Spectrum on the subject. "But when you look at animals with very simple control systems, like sea jellies, it turns out that with some carefully targeted stimulation, they can move faster and more efficiently than they do naturally."

"We present a biohybrid robot that uses onboard microelectronics to induce swimming in live jellyfish," Nicole Xu and John Dabiri write in their paper's abstract introducing the cyborg jellies. "Measurements demonstrate that propulsion can be substantially enhanced by driving body contractions at an optimal frequency range faster than natural behaviour. Swimming speed can be enhanced nearly threefold, with only a twofold increase in metabolic expenditure of the animal and 10 mW of external power input to the microelectronics.

"Thus, this biohybrid robot uses 10 to 1000 times less external power per mass than other aquatic robots reported in literature. This capability can expand the performance envelope of biohybrid robots relative to natural animals for applications such as ocean monitoring."

The cyborgization comes from a TinyLily Mini, originally designed for wearable projects and featuring a Microchip ATmega328P microprocessor with Arduino IDE compatibility. Signals from the microcontroller increase the jellies' natural bell contraction frequency - the movement which provides their locomotion — to around 2.8 times their natural rate, but with only a doubling in metabolic cost.

It's something that wouldn't have been obvious from monitoring the animals in their natural environments: "The presence of efficient enhanced propulsion suggests that A. aurita have latent swimming capabilities," the pair write, "because increasing swimming speeds do not result in disproportionally high gains in animal energy expenditure. Because enhanced propulsion is not naturally exhibited by this species, external stimulation has been required to discover these capabilities."

The full paper has been published in the journal Science Advances under open access terms; additional coverage is available on IEEE Spectrum.

Gareth Halfacree
Freelance journalist, technical author, hacker, tinkerer, erstwhile sysadmin. For hire: freelance@halfacree.co.uk.
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