Journal of Bionic Engineering (2023) 20:530–542https://doi.org/10.1007/s42235-022-00273-2

Design of an Active Flexible Spine for Wall Climbing Robot Using Pneumatic Soft Actuators Guangming Chen1  · Tao Lin1  · Gabriel Lodewijks2  · Aihong Ji1

1 Lab of Locomotion Bioinspiration and Intelligent Robots, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, 29 Yudao Street, Nanjing 210016, China 

2 School of Engineering, College of Engineering, Science & Environment, University of Newcastle, Callaghan Campus, University Drive, Callaghan, NSW 2308, Australia

AbstractWall climbing robots can be used to undertake missions in many unstructured environments. However, current wall climbing robots have mobility difculties such as in the turning or accelarating. One of the main reasons for the limitations is the poor fexibility of the spines. Soft robotic technology can actively enable structure deformation and stifness varations, which provides a solution for the design of active fexible spines. This research utilizes pneumatic soft actuators to design a fexible spine with the abilities of actively bending and twisting by each joint. Using bending and torsion moment equilibriums, respectively, from air pressure to material deformations, the bending and twisting models for a single actuator with respect to diferent pressure are obtained. The theoretical models are verifed by fnite-element method simulations and experimental tests. In addition, the bending and twisiting motions of single joint and whole spine are analytically modeled. The results show that the bionic spine can perform desired deformations in accordance with the applied pressure on specifed chambers. The variations of the stifness are also numerically assessed. Finally, the efectiveness of the bionic fexible spine for actively producing sequenced motions as biological spine is experimentally validated. This work demonstrated that the peneumatic spine is potential to improve the spine fexibility of wall climbing robot.

 Keywords Active spine · Bionic design · Soft robot · Gecko locomotion · Finite-element modeling