Researchers at the Foundation for Research and Technology in Heraklion, Greece created a robot modeled after an octopus to study the near-wake vortex patterns created by octopus limbs. Earlier this year, they put the robot in the Mediterranean Ocean and found the mechanical device left the fish unphased. The scientists now hope to attach a camera to the head of the robotic octopus, so they can use it to study the fish in an unobtrusive way.
Early designs of the robot included fully separated legs which moved the robot moved nearly 4 inches per second. Later, the researchers adopted a design that incorporated fleshy structures between the legs and the robot was obviously able to displace more water and move much faster: more than 7 inches per second. The video below shows the different designs and the relative speed.