High-performance PVA/xanthan gum hydrogel via dual cross-linking with ionic treatment for wearable sensing and hydrovoltaic energy generation

Abstract

Developing advanced materials that balance stretchability, conductivity, and biocompatibility is essential for next-generation stretchable devices. This study reports a highly conductive and stretchable hydrogel engineered from polyvinyl alcohol (PVA) and xanthan gum (XG) using a dual cross-linking method followed by sodium persulfate treatment. The optimized hydrogel exhibited exceptional mechanical robustness, achieving a tensile strength of 1.31 MPa, elongation at break of 410.2%, and toughness of 3.16 MJ/m3. Concurrently, it demonstrated superior electrical performance with an ionic conductivity of 5.23 S/m and minimal electrical hysteresis, making it ideal for dynamic applications. Its utility as a wearable wireless sensor was confirmed by accurately tracking diverse human motions, with machine learning models classifying these movements with 84.91% accuracy. Furthermore, the hydrogel demonstrated potential for sustainable energy generation via the hydrovoltaic effect, producing a peak power density of 20.62 mu W/m2 from salinity gradients. This work presents a versatile PVA/XG hydrogel platform with significant promise for wearable electronics, human-machine interfaces, and osmotic energy harvesting. The combination of excellent mechanical properties, high conductivity, and demonstrated functionalities highlights its potential for cutting-edge technological applications.