Journal of Bionic Engineering (2025) 22:1049–1059https://doi.org/10.1007/s42235-025-00668-x

Design and Implementation of a Miniature Stingray-inspired Robot

Xiongqian Wu1  · Silin Chen2  · Qianqian Chen1  · Wei Wang1  · Jiawei Dong1  · Haifei Zhu1  · Yisheng Guan1  · Tao Zhang3

1 School of Electro-mechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China 

2 School of Mechanical and Electrical Engineering, Guangzhou University, Guangzhou 510006, China 

3 School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China

Abstract 

As marine resources gain increasing significance, the development of high-performance propulsion systems has become a critical area focus in underwater robotics research. Drawing inspiration from the unique symmetrical morphology and highly agile oscillatory propulsion of stingrays, a compact stingray-inspired robot has been developed. This robot integrates multiple functional components, including a head, an oscillating guide rod mechanism, a flexible undulatory fin propulsion mechanism, a hybrid-material drive shaft, a control system, an energy supply unit, and a tail. Driven by three motors, the hybrid-material drive shaft facilitates efficient power transmission to each undulatory propulsion unit at varying angles, ensuring consistent and stable propulsion. The robot demonstrates advanced maneuverability, capable of performing 360° rotations and S-shaped trajectories on the water surface. Furthermore, its flexible drive shaft enables three-dimensional underwater locomotion through precise control of bending angles. With a compact design measuring 270 mm in length, 270 mm in width, and 45 mm in height, and weighing only 346 g, the stingray-inspired robot achieves a maximum swimming speed of 0.617 body lengths per second (BL/s). This stingray-inspired robot holds significant potential for applications in underwater environmental monitoring, covert military reconnaissance, and aquaculture. 

Keywords Stingray-inspired robot · Oscillatory propulsion · Mechatronic system design · Rigid-flexible coupling mechanism