Universal Water Transfer Printing Enables Scalable Structural Coloration of Responsive Textile Fibers for Wearable Electronics

Bioinspired structural coloration of responsive functional fibers is of paramount significance for smart wearable textiles and electronics. Advanced chiral liquid crystals (CLCs) have been regarded as one of the most promising candidates, yet scalable self-assembly onto sophisticated surfaces of microscale curved fibers remains challenging. Here, water transfer printing (WTP) is pioneered as a universal strategy to judiciously transfer and radially align CLC-based structural color onto various fiber surfaces. Well-controlled self-assembly of CLCs with radially aligned helical nanostructures onto fiber surfaces are achieved by elucidating the WTP hydrodynamics of CLCs at the air-water interface. Integrating WTP with coaxial extrusion, meter-long core-multishelled electronic fibers (StructroE-fibers) are continuously fabricated, which comprise a radially aligned CLC photonic sheath, a uniform liquid crystal elastomer actuation layer, and a liquid metal sensing core. StructroE-fibers demonstrate excellent mechano-thermo-electrochromic optical outputs under external stimuli. When woven into textiles, resulting sensing gloves enable real-time stress visualization in human hand and unprecedented human-machine interaction for controlling robot hand movements. This research can offer significant insights into bioinspired structural coloration of sophisticated fibers, and large-scale fabrication of StructroE-fibers for bridging optical and electronic functionalities, opening new avenues for their practical applications in smart textiles, wearable electronics, artificial intelligence, and beyond.