Is there anything more captivating than watching a jellyfish slowly propel itself through the water? I could spend hours at an aquarium watching these majestic creatures dance back and forth. But jellyfish might be more vital to the health and wellness of our oceans than I could have ever imagined. These enticing invertebrates might be the solution to our oceanic pollution problems. No, I’m not suggesting that we arm jellyfish with cleaning supplies and tell them to get to work. These creatures’ unique design, however, is inspiring makers and designers throughout the world as they engineer new ways to remove garbage from the water.

Roboticists at the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart, Germany, have taken inspiration from jellyfish and engineered an underwater robot to collect waste from the bottom of the ocean. The team published their finding in Scientific Advances. The paper, “A versatile jellyfish-like robotic platform for effective underwater propulsion and manipulation,” outlines how their 16-cm-diameter, noise-free prototype can be used to manipulate objects beneath the water’s surface without disturbing nearby species. The machine, dubbed the HASEL jellyfish robot, is approximately the same size as an adult Aurelia aurita also known as the moon jellyfish. According to the research team, the robot is powered by a combination of hydraulically amplified self-healing electrostatic (HASEL) actuators and a hybrid structure of rigid and soft components. The robot, which uses fluid flow to propel itself, has an against-gravity speed of up to 6.1 cm/s and only requires 100 mW of power. Unlike other comparable robots, the HASEL jellyfish robot can trap objects underneath its body without physical contact. 

In an excerpt from the paper, team members note, “Given the design and the individual lappet controllability, the robots introduced here fulfilled diverse underwater functions, such as contact-based and contactless object manipulation, fluid mixing, shape adaptation, and steering, without using any bulky or rigid transmission mechanisms. Next, on top of a single robot design, we demonstrated that a team of these robots could further enhance their object manipulation capabilities. Last, we developed a fully wireless prototype and tested it outdoors; all the power and electronics were integrated onboard. This new noise-free robotic jellyfish platform, along with the demonstrated advances in both propulsion performance and practical functions, will help inspiring the next generation of underwater vehicles for real-world applications.”

Tianlu Wang, a postdoc in the Physical Intelligence Department at MPI-IS and first author on the paper, said, "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. Our robot, too, circulates the water around it. This function is useful in collecting objects such as waste particles. It can then transport the litter to the surface, where it can later be recycled. It is also able to collect fragile biological samples such as fish eggs. Meanwhile, there is no negative impact on the surrounding environment. The interaction with aquatic species is gentle and nearly noise-free"