Design of Soft Pneumatic Actuator in Hand Rehabilitation Robot with FEM-Based Modeling

One motor function stroke patients often struggle with is hand movement, specifically in the hands and fingers. Routine rehabilitation is necessary for the patient to regain their hand-motor skills, which can be achieved using rehabilitation robots. However, traditional rehabilitation robots use rigid electro-mechanical approaches that lack personalization. Soft robotics with an electro-pneumatic approach is a more effective solution, utilizing soft pneumatic actuators (SPA) that are customizable and fabricated with 3D printing, such as pneumatic network structure (Pneu-Net). However, manufacturing every designed Pneu-Net model will require a lot of printing costs and testing time. This study used finite element method (FEM) modeling to streamline Pneu-Net design, fabrication, and testing. The SPA material was modeled using a hyperelastic modeling approach. The bending angle characteristics of the SPA model were simulated for specific pressure inputs using Abaqus CAE software. The results show that the hyperelastic model accurately represents the SPA's performance in real-world conditions with average errors for three sets of material parameters being 7.93%, 6.65% and 7.20%.