Kilogram-scale production of strong and smart cellulosic fibers featuring unidirectional fibril alignment

Abstract

Multifunctional fibers with high mechanical strength enable advanced applications of smart textiles, robotics, and biomedicine. Herein, we reported a one-step degumming method to fabricate strong, stiff, and humidity-responsive smart cellulosic fibers from abundant natural grass. The facile process involves partially removing lignin and hemicellulose functioning as glue in grass, which leads to the separation of vessels, parenchymal cells, and cellulosic fibers, where cellulosic fibers is manufactured at kilogram scale. The resulting fibers show dense and unidirectional fibril structure at both micro- and nano-scales, which demonstrate high tensile strength of ∼0.9 GPa and Young's modulus of 72 GPa, being 13- and 14-times higher than original grass. Inspired by stretchable plant tendrils, we developed humidity-responsive actuator by engineering cellulosic fibers into spring-like structure, presenting superior response rate and lifting capability. These strong and smart cellulosic fibers can be manufactured at large scale with low cost, representing promising fiber material derived from renewable and sustainable biomass.