An Oriented Interpenetrating Network Structure Multi-Stimuli Responsive Hydrogel

As a recent focal point of research, soft electronics encompass various factors that synergistically enhance their mechanical properties and ensure stable electrical performance. However, challenges such as immiscible conductive fillers, poor phase interfaces, and unstable conductive networks hinder the overall efficacy of these materials. To address these issues, a hydrogel featuring an oriented interpenetrating network structure (OIPN) is developed. The pyrrole monomer is in situ polymerized within the confined space of PVA macromolecular chains at low temperatures, resulting in a double network structure. Subsequently, the conductive hydrogel with an OIPN configuration is synthesized through directional freezing combined with salting out techniques. After doping phytic acid (IP6), non-covalent bonds dynamically reinforce the dual network architecture and the pathways for conductivity transfer. Due to its distinctive OIPN structure, the hydrogel containing 50% PPy and 2.3% IP6 exhibits remarkable conductivity (75 µs mm^-1), excellent stretchability (400%), optimal multi-stimuli sensing responses (mechanical and gaseous stimuli), and outstanding device stability (over 2600 cycles at 40% strain). This multifunctional hydrogel presents a promising strategy for advancing applications in soft electronic materials.