Inspenet, 08 de agosto 2023.
A “jellyfish robot” that is virtually noiseless in operation could be tasked with collecting debris from the ocean floor.
Given the enormous amounts of waste present in ecosystems as delicate as coral reefs, one of the strategies to address this problem is to use robots to carry out cleaning tasks.
However, existing underwater robots are often bulky, with rigid bodies that limit their ability to explore and collect samples in complex and unstructured environments, as well as being noisy due to electric motors or hydraulic pumps. Looking for a more suitable design, scientists at the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart have been inspired by nature, taking jellyfish as their model.
Scientists have developed a hand-sized robot inspired by jellyfish that is highly versatile, energy efficient and virtually silent. This has been called Jellyfish-Bot , an innovative robotic platform resulting from the collaboration between the departments of Physical Intelligence and Robotic Materials of the Max Planck Institute for Intelligent Systems (MPI-IS).
A paper describing this creation, titled “A Versatile Jellyfish-Like Robotic Platform for Effective Underwater Propulsion and Manipulation,” has been published in Science Advances.
For the construction of the robot, the team used electro-hydraulic actuators through which electricity circulates. These work like artificial muscles that drive the robot’s movement. Surrounding these muscles are cushions of air and both soft and rigid components that stabilize the robot and make it waterproof, thus preventing the high voltage from the actuators from coming into contact with the surrounding water.
A power supply periodically delivers electricity through thin wires, causing muscles to contract and expand. This ability allows the robot to swim gracefully and generate eddies under its body.
“When a jellyfish swims up, it can trap objects along its path while creating currents around its body. In this way, you can also collect nutrients. Our robot also circulates the water around it. This feature is useful for picking up objects such as debris particles . You can then transport the trash to the surface, where it can then be recycled. You can also collect fragile biological samples, such as fish eggs. Meanwhile, there is no negative impact on the surrounding environment. The interaction with aquatic species is smooth and almost noiseless,” said Tianlu, a member of MPI-IS Physical Intelligence Department and first author of the paper.
The composition of the jellyfish robot
The robot is made up of several layers: some provide rigidity, while others allow the robot to float and isolate itself. An additional layer of polymer acts as a floating skin. Electrical artificial muscles, known as HASELs, are embedded between the various layers. HASELs are plastic bags that contain liquid dielectric and are partially covered by electrodes. By applying a high voltage across an electrode, it becomes positively charged, while the surrounding water becomes negatively charged.
This combination generates a force between the positively charged electrode and the negatively charged water, which causes the movement of the liquid inside the bags and, in turn, causes them to contract and relax, mimicking the behavior of a real muscle. The HASELs are capable of withstanding the high electrical voltages generated by the charged electrodes and are protected from water by an insulating layer. This feature is crucial, as HASEL muscles have never previously been employed to build an underwater robot .
Jellyfish-Bots can move and catch objects without the need for physical contact , working individually or together. Each robot is faster than other similar devices, reaching speeds of up to 6.1 cm/s. Furthermore, it only requires a low input power, approximately 100 mW, and is safe for both humans and fish in case the polymeric material that insulates it breaks down in the future.
Meanwhile, the robot operates with a noise level indistinguishable from background sounds. In this way, the Jellyfish-Bot interacts smoothly with its environment without causing disturbance, just like its natural counterpart.
Source and photo: https://www.techbriefs.com/component/content/article/tb/supplements/md/briefs/48660
Loading...
