Scientists at Harvard’s School of Engineering and Applied Sciences recently reported the study of a soft octopus-like robot. Unlike robots made entirely of hard metal, soft robots are made of more pliable materials that provide resiliency and flexibility. Octopuses are popular inspirations for robots, because their strong flexible tentacles, equipped with rows of suction-providing suckers, can maneuver in small and complicated spaces and tightly grip objects of different shapes and sizes.
The team noted that many octopus-inspired robots often have arms that are shaped like perfect cylinders. Real octopuses, however, have tapered arms that are thicker where they meet the body than they are at the end. By looking at photographs of octopuses from different species, the researchers determined what degrees of tapering were reasonable for their robot. They then used computer modeling software to predict how much an arm would curve based on the pressure applied and the amount of tapering.
Once the ideal amount of taper was determined, the team built an arm with 17 suction cups in two rows. Inside the arm was a vacuum used to help the suckers grasp objects. They found the robot could successfully pick up and manipulate a variety of objects. It was able to pick up, roll, and deliver a piece of paper, as well as pick up an exercise ball, cell phone, coffee cub, egg, and crab. Measurements showed that the tapered tentacle required more force to remove it from an object. It also came apart from the objects one sucker at a time, as opposed to all at once for the tapered arm.
Future work could be used to further study how the angle of tapering allows robots to interact with objects of different sizes, shapes, and roughnesses. Other parameters, such as the types of materials used, more complicated robot motion, and changes in sucker size and placement, could also be varied to allow the robot to manipulate different objects. The performance of robots with tapered arms could give insight on how different species of octopus, which have greatly varied tentacle shapes, are adapted to navigate their environments and catch their preferred prey. Additionally, these octopus arms can have a wide range of uses in industrial applications, replacing clumsy ‘claw-like’ grippers with these agile and improved suction grippers.
Managing Correspondent: Emily Kerr
Image Credit: Togabi: Wikicommons