3D-PSA: A 3D Pneumatic Soft Actuator with Extending and Omnidirectional Bending Motion

Soft robots are increasingly and extensively being investigated and have revealed their potential and wide applications owing to their high flexibility, adaptability, and friendly human-robot interaction. However, existing soft robots commonly have certain disadvantages such as complexity and bulk. To solve this problem, this paper addresses a lightweight, spatial, pneumatic soft actuator with extending and omnidirectional bending motion capability, called 3D-PSA. Geometric parameter optimization using the finite element method is applied to an optimal design, and the molding fabrication process is also presented. According to the geometrical and motion features of 3D-PSA, kinematic mapping from actuation space to the configuration space, and from the configuration space to the task space, is established, and the workspace is analyzed. To verify the motion capability and performance of 3D-PSA, a close-looped pneumatic control system is developed. In addition, some tests are conducted to measure the static and dynamic characteristics for further properties of 3D-PSA.