Design, Modeling, and Application of Bioinspired High-Force-Output Soft Pneumatic Bending Actuator

Soft robotic devices, known for their high compliance, are increasingly being used in assistance and rehabilitation. However, the limited force output of soft actuators has hindered their broader adoption. In this study, a lobster-tail-inspired high-force-output soft pneumatic bending actuator (SPBA) is developed, featuring a soft deformable body and a rigid kirigami limiting shell. The SPBA, with a radius of 10 mm, can generate forces of approximately 22 N at an internal pressure of 0.1 MPa and 36.43 N at 0.16 MPa. An analytical model based on the Euler–Bernoulli beam theory, incorporating a hyperelastic material model, has been constructed to predict the deformation and force of the actuated SPBA. This model demonstrates good agreement with simulated and experimental results. For assistance, a soft robotic gripper with four SPBAs can lift a weight of 5.38 kg at 0.26 MPa. For rehabilitation, an SPBA-based hand exoskeleton has been developed, demonstrating significant effectiveness in mitigating hand spasticity following strokes. This study introduces a novel SPBA design with promising potential for future applications in grasping, assistance, and rehabilitation.