On December 8^th,2021, Associate Professor Chen Rui’s research group of College of Mechanical and Vehicle Engineering of Chongqing University published a research paper titled “Legless Soft Robots Capable of Rapid, Continuous, and Steered Jumping” on Nature Communications. Chongqing University is the first signing institution, Associate Professor Chen Rui and postgraduate Yuan Zean of Chongqing University, Associate Professor Guo Jianglong of Harbin Institute of Technology (Shenzhen), Professor Bai Long of Chongqing University are the co-first authors of this paper, associate Professor Chen Rui of Chongqing University and Professor Pu Huayan of Shanghai University are the co-corresponding authors.

As an important locomotion function of terrestrial robots, jumping or leaping is useful for them to effectively extend their navigation range, overcome challenging obstacles, and enhance their adaptability in unstructured environments. However, enhancing single-jump performance (jumping height(JH) and jumping distance (JD)) of soft jumping robots to improve their obstacle-crossing ability and accelerating jumping frequency to increase their navigation efficiency at the same time are two grand engineering challenges. only few soft jumping robots can achieve rapid continuous jumping and controlled turning locomotion for obstacle crossing.

To solve the problem of low driving efficiency and insufficient reliability of soft robots in an unstructured environment, this paper presents an electrohydrostatically driven tethered legless soft jumping robot capable of rapid, continuous, and steered jumping based on a soft electro hydrostatic bending actuator. This 1.1 g tethered soft jumping robot can achieve a jumping height of 7.68 body heights and a continuous forward jumping speed of 6.01 body lengths per second. Combining two actuator units, it can achieve rapid turning with a speed of 138.4°/s, which is the fastest among existing soft jumping robots. The two robots have strong movement and obstacle capabilities which can be applied to complete environmental perception and detection tasks in some narrow unstructured environments by attaching some temperature and humidity sensors. This work provides a foundation for the application of electro hydrostatic actuation in soft robots for agile and fast multimodal locomotion. The research work provides a new driving mode and design method for the flexible movement of soft robots in an unstructured environment and lays the foundation for the application of electrohydrostatically driven technology in soft robots.

This work was supported by the National Key Research and Development Project of China and the National Natural Science Foundation of China.

Paper：https://www.nature.com/articles/s41467-021-27265-w

LSJR detailed design and motion principle: (a) The LSJR consists of two plastic semicircular pouches printed with flexible electrodes. (b) The LSJR prototype (c) Schematic diagram of the LSJR jumping process. (d) Cross-sectional views (e) Snapshots of the LSJR jumping