Development and Experiment of Manta Ray-Inspired Robot Actuated by Dielectric Elastomer Actuator

The manta ray-inspired robots have attracted widespread attention. Although, current biomimetic pectoral fins actuated by soft actuators have realized simple oscillating motion, the biomimicry needs to be improved and the strategies for improving swimming performance also need to be further investigated. In this study, a manta ray-inspired robot actuated by dielectric elastomer actuator (DEA) is developed. To achieve the large flapping amplitude of biomimetic pectoral fin, an oscillating guide bar mechanism is used to amplify the output capability of DEA. The experimental research was conducted to investigate the influence of flexible deformation of pectoral fin on swimming performance. The locomotion of the biomimetic pectoral fin has been evaluated based on the motion capture and compared with the natural manta rays quantitatively. The results indicate that oscillating motion with biological traveling wave can achieve faster swimming velocity, greater thrust, and higher efficiency. The maximum swimming velocity of biomimetic manta ray robot is 36 mm/s, and the power efficiency is up to 20.1%. The turning test of robot fish is used to verify the maneuverability (8.5°/s). Our work highlights the development and experimental study of the DEA-driven robotic manta ray, which are potentially extendable to other underwater devices and robots.