Analysis of a Variable Stiffness Soft Actuator for Lower Back Pain Rehabilitation

This work presents an analysis of a soft actuator that has customizable stiffness, using the concept of chain mail jamming. The actuator has the ability to achieve adaptive stiffness in a wearable exosuit designed for spinal rehabilitation. It can reshape and exert variable force to aid in this process. The jamming phenomenon occurs when particles within a pliable enclosure become entangled due to the application of pressure along their borders. This is commonly used in the construction of mechanisms that have adjustable stiffness. Chain mail has a smaller packing fraction and offers greater tensile force in comparison to standard jamming media. This work introduces the application of chain mail jamming to soft wearable robotics. Finite Element Analysis confirms the benefits of customizable stiffness in a wearable exosuit for spinal rehabilitation.