A consortium of European researchers is designing a robotic octopus they say will be the first entirely soft robot. A prototype can now manipulate its flexible tentacles to shoot itself through water in a movement that's known as sculling, as well as grasp objects and move via gaits not possible for the real animal.
The European Commission-funded OCTOPUS project is building a robotic octopus body and brain that will be able to propel itself through water, elongate its arms, and use them to reach and grasp items. The research team is studying how all eight arms interact with each other and with the body to achieve locomotion and manipulation of objects.
Real octopi can crawl on the ocean's bottom as well as swim. They propel themselves through water, sometimes at very fast speeds, by combining an internal organic waterjet with coordinated movements of their eight tentacles. Using all eight at once in a certain pattern is called sculling. The prototype octopus, however, can also move its tentacles independently.
A research team at the Foundation for Research and Technology - Hellas, an OCTOPUS partner, presented a paper describing its experiments with robotic octopus gaits at the 2013 IEEE International Conference on Robotics and Automation in Karlsruhe, Germany. In the abstract of the paper, "Octopus-inspired Eight-arm Robotic Swimming by Sculling Movements," the team said it looked at several different swimming gaits and their effects on propulsion. Results of experiments conducted inside a water tank by a robotic prototype with eight arms confirmed previous experiments, which were done with simulations examining the contributions of fluid drag using a dynamic model of the robot.
The in-tank experiments demonstrated that the gaits using sculling-only movements let the robot reach a maximum speed of 0.2 body lengths per second. You can watch a video here that shows simulated gaits, as well as one prototype with rigid arms and its movements, followed by one with soft, compliant arms that move more realistically. The Foundation for Research and Technology - Hellas team that presented the paper includes Michael Sfakiotakis, Asimina Kazakidi, Nikolaos Pateromichelakis, and Dimitris P. Tsakiris.
As we've previously reported, soft robots have several advantages over rigid ones, including changing the shape of their bodies to maneuver through tight spaces. DARPA is investigating some soft robot designs by way of researchers at Harvard University's Wyss Institute for Biologically Inspired Engineering and the university's department of chemistry and chemical biology.
In that R&D project, fluids and air are pumped through a tether into a network of microfluidic channels inside a soft, starfished-shaped robot. This changes the robot's surface temperature, color, luminescence, and apparent shape. These changes make it capable of either blending with its environment, or glowing. Pumped air and fluid also govern its movements. Applications include search-and-rescue operations, or medical applications such as prosthetics technology and simulating fluid vessels and muscle motion to help doctors plan surgeries.
Like DARPA's starfish-shaped soft robot, the EC-funded robotic octopus is also being developed because of its ability to change its form, letting it squeeze into very small spaces and then get out of them again. Interestingly, some of the same researchers in the DARPA-funded project developed the first soft, silicone robots by modeling them after squid and other cephalopods.
|Author:||Ann R. Thryft|