Flexible PEDOT:PSS/PVA Temperature Sensor for Cost-Effective Wearable Medical Devices

The development of flexible and biocompatible temperature sensors is critical for wearable healthcare applications, enabling continuous and non-invasive body temperature monitoring. This paper presents a temperature sensor based on a PEDOT:PSS/PVA composite fabricated using a straightforward drop-casting method encapsulated with polydimethylsiloxane (PDMS) for enhanced durability and biocompatibility. The device is based on the negative temperature coefficient (NTC) charateristics of the fabricated composite polymer, facilitating accurate measurement of temperature alterations. The fabricated sensor demonstrates consistent performance across a physiological temperature range $\left(32^{\circ} \mathrm{C}-40^{\circ} \mathrm{C}\right)$, achieving a temperature coefficient of resistance (TCR) of $0.68 \%{ }^{\circ} \mathrm{C}$. Measurements show a stable decrease in resistance when the sensor is in touch with human skin, reflecting its sensitivity to skin temperature changes. Experimental results show that the resistance returned to its initial baseline; highlighting the repeatability of the sensor and its reliability for dynamic monitoring. The encapsulation with PDMS further enhances the flexibility of the sensor and protects it against environmental hazards while maintaining its electrical and mechanical performance intact. Compared to existing flexible temperature sensors, this device offers a practical balance of sensitivity, flexibility, and ease of fabrication. Its simple design and scalable fabrication make it suitable for various wearable medical applications, including fever detection, thermal mapping, and integration into advanced health monitoring IoT systems. This study contributes to the advancement of flexible electronics for personalized healthcare solutions.