Bio-inspired Scaly Cu/Ag Coating on Regenerated Cellulose Fiber via Self-Assembly for Facile Motion Sensing

Abstract

A facile, scalable, and bioinspired approach was used to create a high-performance, biodegradable motion sensing through the construction of a scaly conductive coating on regenerated cellulose fibers (RCFs) derived from bacterial cellulose. A single-step dip-coating process enabled the in situ self-assembly of copper nanoplates and silver nanoparticles into a multilayered, overlapping architecture during controlled fiber withdrawal, mimicking the flexible yet robust structure of fish scales. The obtained Cu/Ag-RCFs sensor exhibited an exceptional balance of mechanical durability, electrical conductivity, and tunable electromechanical response. Their sensitivity and dynamic range could be precisely tailored by adjusting the number of coating cycles, with the optimized device (4 cycles) delivering stable, reversible, and highly reproducible resistance changes under both bending and tensile deformations. Practical applicability was demonstrated through preliminary demonstrations, including successful integration into a glove for real-time finger gesture recognition and deployment as a vibration monitor for intelligent logistics. Critically, the cellulose-based substrate ensured environmental sustainability, maintaining operational stability in aqueous environments while enabling rapid, complete degradation in acidic or enzymatic conditions. This work establishes a novel paradigm for sustainable electronics that harmonizes bioinspired design, high sensing performance, and end-of-life biodegradability.