Multiscale Engineering of Ion-Conducting Gels for Sustainable Bioelectronic Systems

Ion-conducting gels are indispensable for bioelectronics, offering softness, high ionic conductivity, and biocompatibility. Nevertheless, sustaining robust performance under physiological conditions demands moving beyond isolated material or device innovations to a unified, multiscale design approach. At the material level, advances in polymer network engineering enable precise tuning of ion mobility, retention, and electrochemical stability, while simultaneously imparting mechanical toughness, hydration preservation, and self-healing. At the device level, these gels are tailored for seamless electrode integration, ensuring high signal fidelity, low impedance, and stable ionic-electronic coupling under deformation. When integrated into closed-loop architectures encompassing biosignal acquisition, signal processing, and feedback control, ion-conducting gels evolve from passive conductors into active, reconfigurable elements within autonomous diagnostic and therapeutic systems. This review highlights the critical interplay of material design, device integration, and system-level engineering in advancing long-lived, sustainable bioelectronic technologies.