Tailoring Surface and Self‐Healing Properties of Crosslinked Poly(Ionic Liquid)s for Wearable Applications

Abstract Crosslinked poly(ionic liquid) (PIL) films have emerged as promising candidates for wearable electronics due to their tunable conductivity, mechanical properties, and intrinsic self‐healing ability. In this study, PIL films are synthesized from 3‐hydroxypropyl‐1‐vinylimidazolium bromide (VHPImBr) and systematically vary the crosslinker ratio of poly(ethylene glycol) dimethacrylate (PEGDMA) to modulate film performance. Surface topography, modulus, and adhesion force are analyzed using atomic force microscopy (AFM), while impedance spectroscopy reveals that lower crosslinker content leads to higher ionic conductivity. Self‐healing capability is demonstrated at room temperature, with AFM confirming partial recovery in mechanical and interfacial properties. Furthermore, colloidal force microscopy using a gelatin‐functionalized AFM tip quantifies friction against skin‐like surfaces, highlighting the PIL 10x formulation as the optimal balance between conductivity, mechanical robustness, self‐healing, and user comfort. These findings offer valuable insights for designing soft, self‐healable materials tailored for next‐generation wearable applications.