Shifu-Inspired Fungal Paper Yarns

Fungal biorefinery is a popular method for producing advanced fabrics but is currently limited to leather alternatives and similar by the sheet-based nature of most fungal materials. Biopolymers in the fungal cell wall, such as chitin and chitosan, are only soluble in harsh chemicals, making established extrusion-based yarn production systems expensive and hazardous. The Japanese art of Shifu is used to produce fungal chitin-β-glucan yarns of varying linear density from engineered fungal sheets, enabling the production of yarns. Yarn mechanical strength is influenced by sheet precursor grammage and can be tuned using various chemical modifications such as glycerol-based plasticization. Yarns hybridized with nanocellulose exhibited low strength, stiffness, and ductility, due to weak interfacing with fungal sheets. With mechanical properties outperforming commercial cellulose paper yarns and on par with cotton and viscose yarns, fungal yarns produced from engineered sheets of fungal biomass using Shifu techniques represent a viable yarn candidate for a broad range of applications, yet unachieved using fungi, such as textiles, upholstery, and carpets for the fashion and décor sectors.