Jellyfish cannot do much besides swim, sting, eat, and breed. They do not even have brains. Yet, these easy creatures can easily journey to the depths of the oceans in a way that humans, despite all our sophistication, cannot.
But what if humans could have jellyfish explore the oceans on our behalf, reporting back what they find? Latest research conducted at Caltech goals to make that a reality through the creation of what researchers call biohybrid robotic jellyfish. These creatures, which may be considered ocean-going cyborgs, augment jellyfish with electronics that enhance their swimming and a prosthetic “hat” that may carry a small payload while also making the jellyfish swim in a more streamlined manner.
The work, published within the journal Bioinspiration & Biomimetics, was conducted within the lab of John Dabiri (MS ’03, PhD ’05), the Centennial Professor of Aeronautics and Mechanical Engineering, and builds on his previous work augmenting jellyfish. Dabiri’s goal with this research is to make use of jellyfish as robotic data-gatherers, sending them into the oceans to gather details about temperature, salinity, and oxygen levels, all of that are affected by Earth’s changing climate.
“It’s well-known that the ocean is critical for determining our present and future climate on land, and yet, we still know surprisingly little concerning the ocean, especially away from the surface,” Dabiri says. “Our goal is to finally move that needle by taking an unconventional approach inspired by one among the few animals that already successfully explores your entire ocean.”
Throughout his profession, Dabiri has looked to the natural world, jellyfish included, for inspiration in solving engineering challenges. This work began with early attempts by Dabiri’s lab to develop a mechanical robot that swam like jellyfish, which have essentially the most efficient method for traveling through water of any living creature. Though his research team succeeded in creating such a robot, that robot was never in a position to swim as efficiently as an actual jellyfish. At that time, Dabiri asked himself, why not only work with jellyfish themselves?
“Jellyfish are the unique ocean explorers, reaching its deepest corners and thriving just as well in tropical or polar waters,” Dabiri says. “Since they haven’t got a brain or the power to sense pain, we have been in a position to collaborate with bioethicists to develop this biohybrid robotic application in a way that is ethically principled.”
Previously, Dabiri’s lab implanted jellyfish with a type of electronic pacemaker that controls the speed at which they swim. In doing so, they found that in the event that they made jellyfish swim faster than the leisurely pace they normally keep, the animals became much more efficient. A jellyfish swimming thrice faster than it normally would uses only twice as much energy.
This time, the research team went a step further, adding what they call a forebody to the jellies. These forebodies are like hats that sit atop the jellyfish’s bell (the mushroom-shaped a part of the animal). The devices were designed by graduate student and lead creator Simon Anuszczyk (MS ’22), who aimed to make the jellyfish more streamlined while also providing a spot where sensors and other electronics may be carried.
“Very like the pointed end of an arrow, we designed 3D-printed forebodies to streamline the bell of the jellyfish robot, reduce drag, and increase swimming performance,” Anuszczyk says. “At the identical time, we experimented with 3D printing until we were in a position to rigorously balance the buoyancy and keep the jellyfish swimming vertically.”
To check the augmented jellies’ swimming abilities, Dabiri’s lab undertook the development of a large vertical aquarium inside Caltech’s Guggenheim Laboratory. Dabiri explains that the three-story tank is tall, relatively than wide, because researchers want to collect data on oceanic conditions far below the surface.
“Within the ocean, the round trip from the surface all the way down to several thousand meters will take a couple of days for the jellyfish, so we desired to develop a facility to check that process within the lab,” Dabiri says. “Our vertical tank lets the animals swim against a flowing vertical current, like a treadmill for swimmers. We expect the unique scale of the power — probably the primary vertical water treadmill of its kind — to be useful for a wide range of other basic and applied research questions.”
Swim tests conducted within the tank show that a jellyfish equipped with a mixture of the swimming pacemaker and forebody can swim as much as 4.5 times faster than an all-natural jelly while carrying a payload. The entire cost is about $20 per jellyfish, Dabiri says, which makes biohybrid jellies a pretty alternative to renting a research vessel that may cost greater than $50,000 a day to run.
“Through the use of the jellyfish’s natural capability to resist extreme pressures within the deep ocean and their ability to power themselves by feeding, our engineering challenge is so much more manageable,” Dabiri adds. “We still have to design the sensor package to resist the identical crushing pressures, but that device is smaller than a softball, making it much easier to design than a full submarine vehicle operating at those depths.
“I’m really excited to see what we are able to learn by simply observing these parts of the ocean for the very first time,” he adds.
Dabiri says future work may give attention to further enhancing the bionic jellies’ abilities. Right away, they will only be made to swim faster in a straight line, akin to the vertical paths being designed for deep ocean measurement. But further research may additionally make them steerable, in order that they may be directed horizontally in addition to vertically.
Funding for the research was provided by the National Science Foundation and the Charles Lee Powell Foundation.
