Keri Collins is modifying the robot to swim backward and up and down. Image: Nic Delves-Broughton/University of Bath
The most vulnerable part of any underwater robot is its propeller, which can be easily damaged on rocky terrain or get caught in submerged plants.
The black ghost knifefish, a South American river species, has no such problem: An undulating fin that runs along its belly propels it through obstacles. Keri Collins, a doctoral student at the University of Bath in England, developed a robot called Gymnobot (for Gymnotiformes, a group of fish species including knifefish) using the fish as a model. The robot’s flexible fin, attached to a rigid body, is tangle-proof, according to laboratory tests. When complete, Gymnobot will help scientists study marine life in coastal waters, where varying terrain and habitats are tricky to navigate.
