Bio‐Derived Polyurethane Ionoelastomers With Hierarchical Dynamic Networks for Ultrawide‐Range Iontronic Pressure Sensing

ABSTRACT Sustainable flexible iontronics remain limited by the concurrent difficulty of reconciling mechanical robustness with dynamic adaptability, and achieving high sensitivity across a broad pressure range. Here, we address these challenges by synthesizing a bio‐derived polyurethane ionoelastomer with a dual‐crosslinked architecture. At operational temperatures, thermoreversible Diels‐Alder covalent bonds maintain thermoset‐like structural integrity, while ionic liquid‐mediated ion‐dipole interactions act as dynamic physical crosslinks. This design enables on‐demand topological rearrangement upon heating, allowing for high‐efficiency self‐healing (90.62% stress recovery) and repeated reprocessing without sacrificing mechanical strength. By combining this robust ionoelastomer with a biomimetic random‐rough interface, we fabricated an epidermis‐inspired capacitive sensor. The device exhibits a high sensitivity of 3339.21% kPa −1 (0–200 kPa) and a broad working range up to 1 MPa. For practical wearable applications, the sensor accurately captures radial pulse waves for cardiovascular monitoring. Furthermore, when integrated into a smart insole and paired with a support vector machine model, it classifies daily human activities with near 100% accuracy. This work provides a sustainable and mechanically robust material platform for advanced flexible tactile sensors.