Dual-sensing nano-yarns for real-time pH and temperature monitoring in smart textiles

Textiles is an excellent candidate for the development of smart wearable electronic devices due to its superior comfort, breathability, and lightweight properties. The integration of flexible electronic devices onto fabric is particularly advantageous for the advancement of future smart wearables. In this study, we developed highly sensitive pH-sensing and temperature-sensing nanoyarns featuring a coaxial structure by combining conjugate spinning technology with in-situ polymerization techniques. The pH-sensing nanoyarns demonstrated remarkable pH sensitivity ((−47.8 mV/pH), rapid response times (10 s), and excellent linearity (R 2  = 0.993), while the temperature-sensing nanoyarns exhibited a temperature sensitivity of (−1.53 %/℃) along with notable anti-interference capabilities. Utilizing modern knitting technology, we wove cotton yarn together with sensing yarn to create an intelligent electronic fabric that retains high pH sensitivity (−35.3 mV/pH) and outstanding linearity (R 2  = 0.983). Furthermore, this electronic fabric showcased excellent temperature sensitivity (−1.21 %/°C), strong linearity (R 2  = 0.986), and remarkable cyclic stability across the dynamic range from 30 °C to 50 °C. This work not only expands the application of yarn-based sensors in flexible electronic textiles but also provides new application scenarios for monitoring daily human activities, pH, body temperature, and environmental temperature stimuli.