Photo taken on Aug. 3, 2019 shows the prototype of a biomimetic robot in the shape of a manta ray in Xi'an, northwest China's Shaanxi Province. Chinese researchers in Northwestern Polytechnical University have developed a biomimetic robot in the shape of a manta ray, or devilfish, that can flap its wings and slide underwater. As one of the nature's most efficient swimmers, manta rays possess a unique propulsion mechanism with characteristics such as high propulsion efficiency, high mobility and stability, low noise and large load capacity. The researchers created the bionic soft robot prototype modeled on the shape and motion of a manta ray. The prototype, with a wingspan of 80 cm, is powered by a lithium battery and can swim at a speed of up to 1.85 km per hour. The team will test the robot in lake conditions soon and in the open ocean next year. They also plan to load more sensors for visual and sound detection on the robot for further research. (Xinhua/Shao Rui)