Engineers from the University of California, San Diego have built a squid-like robot that can swim and move on its own, creating jets of water. The robot is equipped with its own energy source. It can also carry a sensor such as a camera for underwater research. Researchers detail their work in a recent issue of Bioinspiration and Biomimetics magazine.
“Basically, we recreated all the key features that squid use for high-speed swimming”, explains Michael T. Tolly, one of the senior authors of the article and professor in the Department of Mechanical and Aerospace Engineering at the University of California, San Diego. “This is the first untethered robot that can generate reactive impulses for a rapid movement like a squid, and can reach these reactive impulses by reshaping its body, which improves swimming efficiency”.
This squid robot is made mainly of soft materials like acrylic resin, with a few hard 3D printed and laser-cut parts. The use of soft robots in underwater research is important to protect fish and corals that can be damaged by hard robots. But soft robots tend to move slowly and have difficulty maneuvering.
The research team, which includes robotics and experts in computer modeling and experimental hydrodynamics, has turned to cephalopods as a good model for solving some of these problems. For example, squid can reach the highest speed among aquatic invertebrates thanks to the mechanism of jet propulsion.
Their robot takes a volume of water into its body while storing elastic energy in the skin and flexible ribs. He then releases this energy by squeezing his body and generates a stream of water to move.
The researchers conducted several experiments to find the optimal size and shape of the nozzle that would drive the robot. This, in turn, helped them improve the robot’s efficiency and its ability to maneuver and move faster. The robot’s speed is about 18 to 32 centimeters per second (about 0.8 km per hour), which is much faster than most other soft material prototypes.