Biomimetic spinning of glassy ionogel fibers with tailorable mechanical properties for versatile applications

Abstract

Ionically conductive fibers are considered promising soft materials for flexible electronics; nevertheless, the insufficiency in mechanical properties prohibits their wide investigations and versatile applications. Although glassy polymers typically possess high tensile strength (10–100 MPa), it remains challenging to preserve their outstanding mechanical properties upon solvation and gelation. Moreover, appropriate technique for continuously spinning glassy ionogel fibers is still lacking. Herein, we propose a biomimetic spinning strategy for directly drawing glassy ionogel fibers with designable mechanical and electrical properties. Ionic liquids play critical roles as plasticizer and solvent cross-linker for regulating the rheological behavior of pre-polymerized dope and guaranteeing the success of continuous fiber spinning. The ionogel fibers exhibit tailorable tensile strength (from 1.44 to 61.51 MPa), Young's modulus (from 0.64 MPa to 3.08 GPa), extensibility (from 5.13 to 541.20 %) and toughness (from 1.43 to 60.27 MJ m⁻³), together with 98 % damping capacity, excellent transparency and optimal ionic conductivity of 4.67 × 10⁻² S m⁻¹. These fibers can be woven to build an artificial cobweb with the capability for camouflage, capture, and sensing. Moreover, as proof-of-concept demonstrations, the ionogel fibers are further used for health control through monitoring physiological signals. We believe that this work opens up a viable route for convenient and scalable fabrication of glassy ionogel fibers with modulated properties for versatile applications.