Programming Knitted ExoSkins to Assist with Knee Joint Motion*

Knitted fabrics, depending on how their constituent stitches are patterned, exhibit emergent elasticity with distinct anisotropies. By taking classic knitted patterns and manipulating their unique directed responses, one can construct specialized wearable fabrics, exoskins, that conform to the wearer and possess bespoke properties that assist or augment motion. In this study, we designed programmed knitted exoskins that can provide resistive torques to resist knee joint flexion (i.e., body weight support) and compared their capabilities with off the shelf knee braces currently in market. We investigated the mechanics of the knitted prototypes on a test rig that mimics knee joint motion and extracted the torsional stiffness experienced under motion. By studying how user-specific exoskins can be designed and programmed for a wearer's specific needs (for instance overcoming an injury or combating the effects of aging), we can steer away from bulky and cumbersome exoskeletons commonly made with heavy and uncomfortable components.