Self-Healable,\nLow-Hysteresis, and Notch-Insensitive\nConductive Hydrogels Enabled by Viscoelastic Nanoparticles for Sensitive\nHuman Motion Sensing

Due to the conflicts between the extremely low hysteresis,\ntoughness,\nand self-healing, it still remains challenging for the fabrication\nof hydrogels simultaneously achieving these contradictory properties.\nHere, we established a simple yet reliable strategy to produce tough,\nself-healable, and low-hysteresis conductive polymer hydrogels. The\nconductive hydrogels are fabricated via a one-step emulsion polymerization,\nwhich consists of the continuous acrylamide (AAm)/PEDOT:PSS aqueous\nphase and the dispersed <i>n</i>-butyl acrylate (<i>n</i>BA)/PEGBDB oil phase. In the formed hydrogel network, the\nPAAm polymer chains are covalently cross-linked by the special P<i>n</i>BA/PEGBDB viscoelastic nanoparticles, which play the following\nroles: (1) improving the hydrogel mechanical strength as cross-linker;\n(2) endowing the hydrogel with good self-healing capability via the\ndense boronic ester groups inside; and (3) transmitting the stress\nthrough the reversible deformation to significantly reduce the energy\ndissipation. The resultant PEDOT:PSS-based hydrogels display the combination\nof considerable stretchability, toughness, notch insensitivity, and\nextremely low hysteresis. Meanwhile, the fractured hydrogels can be\nhealed at ambient temperature to restore their functionalities. This\ngeneral yet versatile design strategy provides a solution to well\nbalance the trade-off between the contradictory properties of toughness,\nself-healing, and low hysteresis and opens up new avenues for high-performance\nflexible electronic devices.