Jellyfish Robots Could One Day Clean Up The World’s Oceans

Marine plastic pollution is a bigger problem than some may realize. According to the International Union for Conservation of Nature (IUCN), at least 14 million tons of plastic end up in the ocean every year, with plastic making up 80 percent of all the marine debris found across the water’s surface and deep below.

Such pollution threatens coastal tourism, the health of marine species, food safety and quality (and thereby human health) and has been shown to contribute to climate change.

Among a myriad of solutions and strategies used to aid this challenge has been a fleet of underwater robots that operate to clean up parts of the world’s oceans. But such robots are often bulky with rigid bodies, and unable to explore and sample in complex and unstructured environments. What’s more, they are often noisy and disturbing to the marine life around them due to their electrical motors and hydraulic pumps.

For a more suitable and quiet design, a team of researchers at the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart, Germany decided to look to nature for inspiration. They built a jellyfish-inspired, versatile, energy-efficient and nearly noiseless robot they call Jellyfish-Bot.

Details about the project were published in April in the peer-reviewed science journal, Science Advances.

To build the robot, the team used electrohydraulic actuators through which electricity flows to serve as artificial muscles, powering the robot. Surrounding these “muscles” are air cushions and various components to stabilize the robot and make it waterproof. A quiet power supply provides electricity within, causing the robot to contract and expand. The result is a piece of machinery that can swim gracefully, quickly (6.1 centimeters per second), and looks and moves like a real jellyfish.

“When a jellyfish swims upwards, it can trap objects along its path as it creates currents around its body. In this way, it can also collect nutrients,” explains Tianlu Wang, a member of the research team and postdoc in the physical intelligence department at MPI-IS.

Wang says the Jellyfish-Bot circulates water around it in similar fashion and can operate either alone or with several bots together. “This function is useful in collecting objects such as waste particles,” he says. “It can then transport the litter to the surface, where it can later be recycled.”

What’s more, because the bots are capable of moving and trapping such objects without physical contact, Wang says cleaning up the ocean can be done without negatively impacting the surrounding environment. “The interaction with aquatic species is gentle and nearly noise-free,” he says.

Another member of the team, Hyeong-Joon Joo, explains the reasons they began researching and working on the project in the first place. Because plastic makes up the majority of pollution in the oceans and nearly always sinks to the seabed, “we saw an urgent need to develop a robot to manipulate objects such as litter and transport it upwards,” he says. “We hope that underwater robots could one day assist in cleaning up our oceans.”