A High-Sensitivity, Lamination-Free Stretchable Temperature Sensor Array for On-Skin Wireless Temperature Monitoring and Mapping in Healthcare Applications

Skin temperature is a key physiological signal that reflects conditions such as fever, infection, and localized inflammation, making real-time monitoring essential for early disease detection and health monitoring. This increases the need for temperature sensors that are not only highly sensitive, fast responding, and linear but also light weight, biocompatible, and stretchable to enable the reliable and unobtrusive use in daily life. Herein, we present an intrinsically stretchable thermoresistive temperature sensor based on poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS)/polyurethane dispersion composites that exhibits high sensitivity (-1.1% °C^-1), high resolution (0.1 °C), excellent linearity (<i>R</i>² ≈ 0.98), and fast response and recovery times of 8.5 and 5.2 s, respectively, between 25 and 50 °C. It also sustains a stable operation under ambient conditions and withstands 30% mechanical strain over 10,000 cycles. Finally, the sensor was integrated into a wireless connected 3 × 3 sensor array for real-time temperature monitoring and mapping, with data visualized in real time through a custom-developed smartphone application. Notably, the sensor array was fabricated entirely through a lamination-free solution process, which simplifies the fabrication process and enhances mechanical reliability, making it well suited for direct applications in wearable healthcare systems.