Color-changing has a wide application including electronic display, military camouflage, intelligent switch, intelligent sensor and intelligent fabric. However, slow response, poor controllability and stability are the challenges affecting the currently application of flexible thermochromic materials. This work aims at designing and constructing hierarchical structure of core-coated electro-thermochromic carbon nanotube/polyurethane composite fibers (ECPF) by impregnation and electrospinning, resulting in color-rich and electro-driven thermochromic composite fibers. The results showed that the temperature on the surface of the composite fiber increased from 25 C to 66.4 C and the color changed from red to yellow with the voltage of 9 V applied to both ends of ECPF respectively. The color spectrum of ECPF can be achieved by adjusting the type of color-changing inks, and different patterns of discolored textiles can be realized by weaving. In addition, ECPF composite fibers have excellent conductivity, high sensitivity, a wide strain range (0%–310% strain) and excellent durability (>2000 cycles). The ECPF composite fibers can not only detect human micro-movement, but also exhibit a large strain range more than twice the original length. This work contributes a novel strategy of developing multi-functional electro-thermochromic nanocomposite fibers with color-changing performance and wearable electronic applications for health and human movements monitoring.

变色具有广泛的应用，包括电子显示、军用伪装、智能开关、智能传感器和智能织物。然而，响应慢、可控性和稳定性差是目前影响柔性热致变色材料应用的挑战。本工作旨在通过浸渍和静电纺丝设计和构建包芯电热致变色碳纳米管/聚氨酯复合纤维（ECPF）的分层结构，从而获得色彩丰富的电驱动热致变色复合纤维。结果表明，在ECPF两端分别施加9 V电压，复合纤维表面温度由25℃升高到66.4℃，颜色由红色变为黄色。ECPF的色谱可以通过调整变色油墨的种类来实现，通过编织可以实现变色纺织品的不同图案。此外，ECPF 复合纤维具有优异的导电性、高灵敏度、宽应变范围（0%–310% 应变）和优异的耐久性（>2000 次循环）。ECPF复合纤维不仅可以检测人体微运动，而且还表现出比原始长度两倍多的大应变范围。这项工作有助于开发具有变色性能和可穿戴电子应用的多功能电热致变色纳米复合纤维，用于健康和人体运动监测。高灵敏度、宽应变范围（0%–310% 应变）和出色的耐用性（>2000 次循环）。ECPF复合纤维不仅可以检测人体微运动，而且还表现出比原始长度两倍多的大应变范围。这项工作有助于开发具有变色性能和可穿戴电子应用的多功能电热致变色纳米复合纤维，用于健康和人体运动监测。高灵敏度、宽应变范围（0%–310% 应变）和出色的耐用性（>2000 次循环）。ECPF复合纤维不仅可以检测人体微运动，而且还表现出比原始长度两倍多的大应变范围。这项工作有助于开发具有变色性能和可穿戴电子应用的多功能电热致变色纳米复合纤维，用于健康和人体运动监测。