Revealing Twist Pitch in Helical Electronic Fibers for Improving the Axial Electric Field

Abstract Electronic fibers (E‐fibers) with high flexibility, excellent bendability and twistability, and ease of weaving and integration hold tremendous application potential in smart wearable devices for energy storage, signal transmission, and bioelectronic applications. For commonly used e‐fibers with a helical structure, the uniformity of the internal electric field directly determines their performance. However, the impact of the twist pitch on the internal electric field distribution is long overlooked. Herein, by dynamically tuning the twist pitch of helical e‐fibers, the mechanism of axial electric field enhancement is systematically elucidated. Optimization of fiber twist pitch via customized equipment enables the fabrication of long‐range helical electrochromic (EC)/electroluminescent (EL) fibers, which exhibit an expanded modulation range (53.1%) and enhanced optical power density (19.27 nW cm −2 ). Finally, based on the excellent flexibility and weavability of helical EC/EL fibers, multifunctional display textiles suitable for all‐day wear are fabricated through weaving and embroidery, demonstrating significant potential for applications in smart wearable displays.