Multimodal Wearable Sensors Based on Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) with High Sensitivity, Linearity, and a Wide Range

Abstract

Flexible multifunctional sensors have garnered significant interest for their potential in wearable devices and physiological monitoring. However, achieving both high sensitivity and excellent linearity over a broad sensing range remains a considerable challenge. In this work, we developed a poly(ethylene oxide) (PEO)/poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)@thermoplastic polyurethane (TPU) hybrid film for temperature, humidity, and strain sensing. The PEO/PEDOT:PSS@TPU hybrid film demonstrates remarkable temperature sensitivity (−2.25%/°C between 30 and 60 °C) and high humidity sensitivity (1.91 within 80% RH). By incorporating PEO to enhance the dispersion of PEDOT:PSS and establish a more robust conductive network, the sensor achieves outstanding strain sensitivity (gauge factor = 315.9), excellent linearity (R² > 0.99) across a wide sensing range (0–80%), and high durability (>1000 cycles). Furthermore, the sensor successfully tracks physiological signals, highlighting its promising applications in smart skin and healthcare monitoring.