Journal of Bionic Engineering (2023) 20:2661–2669 https://doi.org/10.1007/s42235-023-00415-0

All-Fabric Bi-directional Actuators for Multi-joint Assistance of Upper Limb

Junlin Ma1 · Diansheng Chen1 · Zhe Liu1 · Jie Wei1 · Xianglin Zhang1 · Zihan Zeng1 · Yongkang Jiang2,3

Diansheng Chen chends@163.com

1 Institute of Robotics, Beihang University, Beijing 100191, China

2 Department of Control Science and Engineering, Tongji University, Shanghai 201804, China

3 Frontiers Science Center for Intelligent Autonomous Systems, Shanghai 201210, China

Abstract： According to clinical studies, upper limb robotic suits are vital to reduce therapist fatigue and accelerate patient rehabilitation. Soft pneumatic actuators have drawn increasing attention for the development of wearable robots due to their low weight, flexibility, and high power-to-weight ratio. However, most of current actuators were designed for the flexion assistance of a specific joint, and that for joint extension requires further investigation. Furthermore, designing an actuator for diverse working scenarios remains a challenge. In this paper, we propose an all-fabric bi-directional actuator to assist the flexion and extension of the elbow, wrist, and fingers. A mathematical model is presented that predicts the deformation and guides the design of the proposed bi-directional actuator. To further validate the applicability and adaptability of the proposed actuator for different joints, we developed a 3-DOF soft robotic suit. Preliminary results show that the robotic suit can assist the motion of the elbow, wrist, and finger of the subject.

Keywords： Soft robotic suits · Fabric-based actuators · Multi-DOF motion · Upper limb rehabilitation