The fastest swimming robot mimics manta rays—are we ready for aquatic robots?

In a groundbreaking study published in the journal Science Advances, researchers at North Carolina State University developed a cutting-edge aquatic soft robot inspired by the swimming mechanics of manta rays. This innovative robot utilizes fins shaped like those of manta rays and is constructed from a flexible material that retains stability when the fins are fully extended. The study, led by Professor Jie Yin, represents a significant advancement in soft robotics, showcasing not only faster movement but also increased energy efficiency compared to previous iterations. The new robot can swim at an impressive speed of 6.8 body lengths per second, surpassing the earlier model that recorded an average speed of 3.74 body lengths per second. This achievement demonstrates the potential for soft robots to operate effectively in a range of aquatic environments, with capabilities to navigate vertically throughout the water column. Professor Jie Yin explained that the new design incorporates a unique air chamber that can be inflated, allowing the fins to mimic the natural swimming motion of manta rays by bending during downstrokes. To optimize the efficiency of its movements, the fluid dynamics mimicking techniques were applied, enabling the robot to adjust its swimming direction and vertical positioning based on the behavior observed in manta rays. The researchers noted that manta rays produce two jets of water, a feature they successfully replicated in their robot. By harnessing this jet propulsion effect, the team aims to enhance the robot’s ability to swim upward, downward, or maintain its depth effectively. The robot's functionality was showcased through practical demonstrations involving obstacle navigation in a water tank and the ability to transport objects across the water surface. This pioneering work indicates that with only a single actuation input, the robot could navigate complex environments while retaining a simplified design structure. Researchers expressed intent to further improve the robot's lateral movement capabilities and to develop fine control techniques in subsequent iterations, highlighting ongoing research and innovative possibilities in soft robotics.