Multifunctional highly stretchable hydrogel with dual strain/temperature sensing for cardiac rehabilitation training

Conductive hydrogels have gained enormous attention for their promising applications in personal health management, medical rehabilitation and human-machine interaction. However, it is still very necessary to develop a multifunctional hydrogel intrinsically integrating dual strain/temperature sensing and thermochromism. Herein, a multifunctional and highly stretchable PAM-PNIPAm-PEDOT: PSS (MNP) hydrogel was developed using a simple and efficient free radical polymerization strategy. The MNP hydrogel not only demonstrates good stretchability (1050 %), transparency and adhesion performance, but also possesses excellent strain sensing performance including wide sensing range (1050 % strain), high sensitivity (maximum GF of 5.72), ultralow detecting limit (0.5 % strain) and good cycle stability (1500 stretching-releasing cycles). These features facilitate its integration into wearable systems, such as smart gloves for gesture recognition and Morse-code-based information transmission. Additionally, its application in cardiac rehabilitation has been validated through real-time monitoring of lower limb movement and temperature fluctuations, offering valuable feedback for personalized training and health management. Moreover, the MNP hydrogel also demonstrates reversible transparency conversion and exceptional temperature-sensing capabilities, enhancing its potential for personalized cardiac rehabilitation and optimizing training intensity.