Plant Template-Based Ultra-high Conductivity Multifunctional Silver Nanocomposite Transparent Hydrogel for Flexible Wearable Sensors

Conductive hydrogels, widely recognized as flexible sensor materials for health monitoring, pose a research challenge in selecting suitable frameworks and designing multifunctional composites that balance conductivity, transparency, self-healing, and mechanical properties. In this work, a simple and efficient plant-template method (corn husk) is used to generate a multifunctional textured hydrogel (PPA) with PEI and PVA as the transparent framework, without additional cross-linking agents. The resulting hydrogel exhibits high conductivity (8.56 S/m), excellent transparency (94% @ 550 nm for the nontextured variant), and remarkable stretchability (627.1%). Additionally, the PPA hydrogel exhibits remarkable self-healing capabilities, achieving a maximum self-healing efficiency of 94.68%. To enhance conductivity, AgNWs are applied to the PPA surface using a rod coating method, forming PPA@RCA with a conductivity of 12.39 S/m. This improvement is attributed to the interactions between the silver-based nanomaterials (AgNWs, AgNPs), Li+, and the PEI/PVA framework in PPA@RCA. The flexible wearable strain sensor based on PPA@RCA features a high gauge factor of 3.35 and instantaneous response characteristics (response time of 195 ms), exhibiting exceptional sensitivity and repeatability across diverse strain ranges and external stimuli. Therefore, the ultrahigh-conductive textured hydrogel, produced through a plant-template strategy, demonstrates significant potential for applications in tablet capacitive pens, writing devices, smart wearables, and health monitoring.