Coaxial Electroluminochromic Fibers with Dynamic RGB Switching for Pixelated Smart Textiles

Abstract The immense potential of electronic textiles for wearable applications has spurred extensive research into luminescent fibers suitable for smart textile displays. However, current electroluminescent (EL) fibers, while flexible and wearable, typically emit only a fixed color and have a 1D structure, which confines fiber‐based displays to pre‐designed patterns. Here, a coaxial hierarchical fiber structure is fabricated with an insulating polymer layer sandwiched between an EL core and an electrochromic (EC) shell based on carbon nanotube fibers. Acting as a dynamic optical filter with RGB tri‐state switching capabilities, the EC shell can effectively modulate the optical properties of inner emitted lights via a low voltage, enabling a new “electroluminochromic” fiber with multicolor luminescence and rapid on‐demand color switching. Moreover, electroluminochromic bare fibers can be woven with orthogonal electrodes at discrete gel polymer electrolyte junctions, forming individually addressable luminescent pixels. Using a warp‐weft knitting approach and integration with the Internet of Things, this display textile can transmit information, exhibiting great potential for applications in smart displays and wearable electronic devices.