Electromechanical Enhancement of Live Jellyfish for Ocean Exploration*

Electromechanical Enhancement of Live Jellyfish for Ocean Exploration:

The vast majority of the ocean's volume remains unexplored, in part because of limitations on the vertical range and measurement duration of existing robotic platforms. In light of the accelerating rate of climate change impacts on the physics and biogeochemistry of the ocean, the need for new tools that can measure more of the ocean on faster timescales is becoming pressing. Robotic platforms inspired or enabled by aquatic organisms have the potential to augment conventional technologies for ocean exploration. Recent work has demonstrated the feasibility of externally stimulating live jellyfish swimming via implanted microelectronics. We present a robotic platform that leverages this external electrical swimming control, while also using a passive mechanical attachment to streamline the jellyfish shape and significantly enhance the payload capacity of the biohybrid robotic jellyfish. A six-meter-tall, 13,600-liter saltwater facility was constructed to enable testing of the vertical swimming capabilities of the biohybrid robotic jellyfish over distances exceeding 35 body diameters.

We found that the combination of external swimming control and the addition of the mechanical forebody resulted in an increase in swimming speeds to 4.5 times natural jellyfish locomotion. Moreover, the biohybrid jellyfish were capable of carrying a payload volume up to 105\% of the jellyfish body volume. The added payload decreased the intracycle acceleration of the biohybrid robots relative to natural jellyfish, which could also facilitate more precise measurements by onboard sensors that depend on consistent platform motion.

The demonstrated performance of these biohybrid robots suggests an opportunity to expand the set of robotic tools for ocean exploration.