Like most things these days, jellyfish too are due for an upgrade. Regarded as the most energy efficient swimmers in water, the umbrella shaped fish with trailing tentacles are not only known to prowl the ocean basement at crushing depths that have so far eluded most ships, submarines, robots and humans. They also do it with stealth and grace without roiling the waters, which makes them the perfect species to manipulate.
Scientists like AAAS Member and 2010 MacArthur Fellow John Dabiri are looking to lift the skin of jellyfish and insert digital chips to create what they are calling bio-inspired robots, or jellyfish under robotic control, to steer their domes into unknown spaces in the hopes that they gather data and an accurate picture of what role the ocean plays in climate change.
"Success of life on earth depends on the ocean…how much carbon the ocean can keep storing for us and other unknowns are important to try and predict what is going to happen in the next five, 10 or 50 years with climate change," says the aeronautics engineer and Centennial Chair Professor at the California Institute of Technology. "We have a general understanding of how the ocean works but we are going to need better data in order to make predictions like that.”
There are other impacts as well. With most of the world’s population expected to be within 50-100 miles of an ocean, accurate data is critical because shipping, fisheries, oil and gas accounts for $6 trillion of ocean economic activity.
At this year’s AAAS Annual Meeting, Dabiri presented his novel approach using remote-controlled jellyfish to some colleagues at the largest virtual scientific gathering in the world. “This is a great opportunity to showcase interdisciplinary research by a number of grad students whom I’ve been fortunate to mentor over the past decade on this topic," he says.
One unexpected application Dabiri has for these jellyfish robots is the study of other swimming organisms in the ocean. Professor Dabiri explains that at sunset, trillions of animals swim to the surface of the ocean to feed. This mass migration that happens daily is similar to a stampede occurring on land, when the surrounding area might be disturbed by animals knocking over trees.
"In the ocean, what happens is that when you have this vertical stampede up to the surface, the surrounding water also gets disturbed and so what we have studied is the effect of the water around these animals getting disturbed. Lab experiments and some field results suggest that the water mixing during that vertical migration can be extremely important for carbon sequestration and for transferring nutrients within the ocean," he says.
Conventional robots, like big submarines, for example, make it very difficult to measure this process in the ocean because animals in those vertical migrations will avoid such a big contraption. Dabiri’s jellyfish robots would be better suited to study the underwater stampede phenomenon.
Explaining his research in layperson’s terms: "I was interested in vortex rings...some people with a cigar can blow out smoke rings or vortex rings as they are called," he says. "Jellyfish, when they swim, they create these vortex rings as they propel themselves in water. It turns out that by studying the shape of those vortex rings and how they are formed, you can learn a lot about the propulsion system, whether that is the jellyfish or your heart, if you think of it as a propulsion system that is propelling blood through your body."
Dabiri's propulsion theory is not only confined to jellyfish in the ocean. He has also extended his field of study to apply to vertical axis systems on wind farms.
"It turns out that the physics that explains water motion is not that different from what controls how air moves in different systems," he notes. "One of the big issues on wind farms today is that each of the wind turbines generate a lot of turbulence which reduces the performance of nearby wind turbines. Our thought was to come up with a way to arrange the wind turbines so that they could take advantage of the air flows of the neighboring wind turbines."
Field experiments conducted by Dabiri and his colleagues confirmed that vertical axis wind turbines can interact synergistically to enhance the total power production when placed in proximity.
“Vertical axis systems, which are different from the propeller type wind turbines, have a much better ability to take advantage of that collective schooling effect like fish," he says. This process not only helps conserve energy, but also retains the aesthetic beauty of large expanses of land that would otherwise be filled with giant propellers. “In Alaska, there are large areas of land with significant wind resources, but installing conventional large wind turbines could impact the view and would require a lot of new electricity transmission. You may not have the infrastructure for that kind of development.”
Next steps for Dabiri? Translating his research to action. "In the President’s Council [of Advisors on Science and Technology, or PCAST], we have already been able to speak to [President Biden] about areas where science and technology can contribute," he says. "For example, we are currently working on the topic of wildfires, which is an impact of climate change and one that seems to be getting more severe," he says. "Fortunately, we have a president who really does care about taking inputs from science in making decisions."