A Compact Soft Robotic Wrist Brace With Origami Actuators.

Sicong Liu,Juan Yi,Zheng Wang,Jianwen Luo,Kailuan Tang,Zhonggui Fang,Xinyao Hu,Jianhui Liu

doi:10.3389/frobt.2021.614623

Sicong Liu, Juan Yi + Show 6 more

Open Access

https://doi.org/10.3389/frobt.2021.614623

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Abstract

Wrist disability caused by a series of diseases or injuries hinders the patient’s capability to perform activities of daily living (ADL). Rehabilitation devices for the wrist motor function have gained popularity among clinics and researchers due to the convenience of self-rehabilitation. The inherent compliance of soft robots enabled safe human-robot interaction and light-weight characteristics, providing new possibilities to develop wearable devices. Compared with the conventional apparatus, soft robotic wearable rehabilitation devices showed advantages in flexibility, cost, and comfort. In this work, a compact and low-profile soft robotic wrist brace was proposed by directly integrating eight soft origami-patterned actuators on the commercially available wrist brace. The linear motion of the actuators was defined by their origami pattern. The extensions of the actuators were constrained by the brace fabrics, deriving the motions of the wrist joint, i.e., extension/flexion, ulnar/radial deviation. The soft actuators were made of ethylene-vinyl acetate by blow molding, achieving mass-production capability, low cost, and high repeatability. The design and fabrication of the soft robotic wrist brace are presented in this work. The experiments on the range of motion, output force, wearing position adaptivity, and performance under disturbance have been carried out with results analyzed. The modular soft actuator approach of design and fabrication of the soft robotic wrist brace has a wide application potential in wearable devices.

Highlights

Disease such as stroke causes upper limb motor impairment
The end plate is screwed to the test platform, and the slider moves in the normal direction of the end plate collinear with the axial deformation of the soft origami actuator (SOA) during test
We proposed a soft-onsoft approach to constrain and preprogram the output of the SOAs, where the extension of the SOAs was constrained by fabrics into consecutive bending

Summary

Introduction

Disease such as stroke causes upper limb motor impairment. The capability of the arm to perform activities of daily living (ADL) is limited due to the loss of motor control (Krakauer, 2005). The timely rehabilitation helps to induce neural plasticity and recovery, the motor recovery (Hendricks et al, 2002), by repetitive movement training or massed practice on the joints (Brewer et al, 2007; Martinez et al, 2013). A number of robotic rehabilitation devices have been developed and employed in the clinical research and therapy (Brewer et al, 2007). The human upper limb consists of complex skeletal structure, which includes shoulder complex, elbow complex, wrist joint, and fingers (Gull et al, 2020). The existing rehabilitation robots provide convenient therapy in a daily living environment but are still facing challenges in kinematic compatibility, discomfort, misalignment, and affordability on the way to broad application

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