Continuous preparation of bio-inspired self-helical wheat gluten conductive fibers for wearable sensors

A green ternary solvent system (Na 2 SO 3 /LiCl/urea) is developed to overcome the poor water solubility of wheat gluten. • Self-helical wheat gluten fibers are continuously fabricated via a one-step wet-spinning process. • The fibers exhibit excellent stretchability (1200% elongation), ionic conductivity, and excellent anti-freezing performance down to −80 °C. • The fibers enable real-time monitoring of human motions, respiratory behaviors, and Morse-code-based information transmission. • A smart glove system is demonstrated for closed-loop human-machine interaction using the helical fibers. With the rapid advancement of wearable intelligent electronics, various high-performance conductive fibers have been developed. However, most of them suffer from an inherent trade-off between electrical stability and mechanical deformability, often failing to maintain consistent conductivity under large or repeated mechanical strain. Inspired by natural helical architectures, wheat gluten (WG) conductive fibers with a self-helical architecture have been successfully developed via a facile wet-spinning technique. To address the intrinsically poor water solubility of pristine WG, a ternary solvent system consisting of Na 2 SO 3 , LiCl, and urea is developed. Continuous self-helical WG fibers are obtained by extruding the spinning dope into a 20 wt% Na 2 SO 4 coagulation bath. The resultant fibers exhibit exceptional mechanical flexibility (with an elongation at break of 1211 ± 85% and a tensile strength of 12.8 ± 1.5 MPa), outstanding anti-freezing performance (stable performance at −80 °C), ionic conductivity (1.59 ± 0.25 mS/m) and distinct humidity-responsive behavior. When assembled into flexible sensors, they enable reliable real-time monitoring of diverse human motions, subtle respiratory signals, and efficient human-machine interactions. Thus, this work provides a green, scalable, and straightforward approach for fabricating self-helical WG conductive fibers, which hold great promise for plant protein-derived wearable electronics in healthcare monitoring and human-machine interfacing applications.