A Fabric-Based Soft Elbow Exosuit with Autonomous Anchoring Straps

Fabric-based soft exosuits offer promising solutions for elbow rehabilitation and assistance owing to their lightweight and flexible nature. However, existing designs usually apply continuous compression on the arm to anchor, whether actuated or not, potentially causing discomfort, numbness, and impaired blood circulation. Here, we present a fabric-based soft elbow exosuit that autonomously adjusts its compressing forces on the arm, harnessing a fabric-lattice artificial muscle (FAM) combined with two X-crossing anchoring straps (XASs) (worn on the upper arm and forearm). When the FAM is deflated, two XASs fit loosely on the arm. When the FAM is inflated, it contracts axially to assist elbow flexion and elongates laterally to actuate two XASs to anchor concurrently. Experimental results show that the FAM can output a contraction force up to 110 N, the XASs can generate a compressing force of 9.7 N (approximately 3 kPa), and the exosuit can provide a considerable torque up to 3.5 N•m, capable of assisting an elbow model to flex to 95°. These results demonstrate that our elbow exosuit provides a new approach to autonomous anchoring while achieving elbow flexion assistance effectively.