Robust and soft eel-like robots can swim gently under water

Engineers and marine biologists at the University of California have created a new eel-like robot that can swim quietly in seawater without an electric motor. Instead, the robot uses artificial muscle to move. This robot is about 30cm long, which is connected to an electronic board mounted on the surface, which is also nearly transparent.

Scientists say the robots are an important step toward future, soft robots can swim in the sea with fish and invertebrates but do not disturb and harm them.

Currently, most vehicles designed to observe marine life are rigid and underwater by electric motors with propellers emitting noises.

"Robots do not make noise," said Caleb Christianson, a graduate student at Jacobs School of Engineering and coauthor of the study .

The new point here is that robots swim in salty water to help generate electrical force that pushes it . The robot is equipped with piezoelectric cables for the saltwater environment around the robot and small pockets inside its artificial muscles. After that, the electronics provide negative charge to the water just outside the robot and positive charge to the inner part of the robot to activate the muscles. The charge is located just outside the surface of the robot and contains very low power current, so it is safe for marine creatures to swim near.

In the past, other teams have created robots with similar technology. But to provide power to these robots, engineers are using materials that need to keep the tension stretching within the hardened part frame. Research on robotic science suggests that there is no need to use these frames.

Robots were tested inside saltwater cisterns with jellyfish, coral and fish at the Birch Aquarium in the Scripps Institution of Oceanography at the University of California and in Tolley's lab. The robot's artificial muscle conduits inside the robot can contain fluorescent dyes. In the future, fluorescent dyes will be used as a signaling system.

The next step, researchers will increase the stability and shape of the robot. Researchers need to improve the ballast, adding more weight to the robot's ability to dive deeper.