Highly Stretchable Ionic and Electronic Conductive Fabric

Wearable devices redefine the way people interact with machines. Despite the intensive effort in the design and fabrication of synthetic fibers to improve wearable device properties in terms of electronic and ionic conductivity, stretchability, comfort, and washability, challenges remain in fabricating single fiber materials that optimize all properties simultaneously. In this work, we demonstrate a highly stretchable, ionic, and electronic conductive fabric via (1) the natural nanoscale channels in fibers for effective ion transportation, (2) confining the electronic conductive material with the cellulose fibers, and (3) decoupling the property degradation of the fiber from deformation using the knitted pattern. The hierarchical structure created by cotton fibers can serve as ionic conductive channels as well as a robust multiscale scaffold to host infiltrated electronic conductive materials. Cotton strands with ionic and electronic conductivity can be knitted into fabrics that are highly stretchable (~ 300%). Moreover, high ionic and electronic conductivity are observed with 2 S/m and 5 S/m, respectively, even under a strain of 175%. With the inherent advantages of cotton fabrics such as moisture-wicking, washability, comfort, and light-weightiness for wearable applications, our approach of directly functionalized cellulose can potentially be a promising route towards highly stretchable and wearable mixed conductors. Graphical Abstract