Research and application of a multi-degree-of-freedom soft actuator

ABS T R A C T In recent years, soft pneumatic actuators with soft and flexible materials have been widely studied in the field of soft gripper and soft bionic robot. Up to present, the soft actuators studied usually have one motion manner such as extending, bending, twisting or rotation. In this paper, we propose a new type of multi-degree-of-freedom soft pneumatic actuator (MDoF SPA) that can extend or rotate in response to pressured air inputted in different chambers. A fabrication method was proposed. A mathematical model based on large deformation theory was presented to predict the elongation displacement and bending angle. Moreover, finite element analysis and experimental investigation were performed to verify the theoretical results. The output force during elongation and blocking force during bending were also tested. Finally, two MDoF SPAs were utilized to fabricate a crawling robot. The gait and hardware of crawling robot were shown. The average moving speed of linear motion, maximum bending angle were investigated as well. Experiments revealed the robot actuated by MDoF SPAs has a good comprehensive performance, which has great potential in search, detection, rescue and other operations in a narrow environment. This work can guide the design and application of MDoF SPAs in the future