Independent dual-responsive Janus chromic fibers

Daily exposure under solar ultraviolet (UV) and infrared (IR) is prone to cause skin cancer and photoaging. Real-time monitoring of the environmental UV index and IR radiation temperature during outdoor activities can enhance awareness and strengthen personal protection. It is a challenge to design flexible, wearable devices (with measurement capabilities) that can be integrated with apparels. Here, microfluidic spinning technology (MST) was used for the continuous and large-scale fabrication of eco-friendly coresheath Janus fibers with a well-defined axially symmetric Janus core. One side of the core was sensitive to UV light and the opposite was sensitive to IR radiation. Textiles woven with Janus fibers showed excellent independent reversible color responses to dual-wavelength stimulation. Such textiles switched among four colors under UV and IR irradiation, both individually and in combination. The color gradient of the textiles changed significantly with increasing UV intensity (UV index). After 60 cycles of UV/IR stimulation and 50 washes, the change rate of the comprehensive chromatic aberration (Delta E*(ab)) of the textiles under different conditions was only 0.42%-4.71%. This was attributed to the unique structure of the fibers. The three-line striped textiles demonstrated the potential of the fibers to be used as wearable energy-free real-time visual monitors of the UV index and IR radiation temperature.

Automated summary

The study utilized microfluidic spinning technology to fabricate eco-friendly coresheath Janus fibers with sensitivity to UV and IR, enabling textiles woven with these fibers to exhibit independent reversible color responses to dual-wavelength stimulation. The color gradient of the textiles changed significantly with varying UV intensity, demonstrating the potential of the fibers to be used as wearable energy-free real-time visual monitors of the UV index and IR radiation temperature.