Engineering Conducting Polymer Hydrogels for Bioelectronic Interfacing

Abstract Bioelectronics promise transformative advances in healthcare through seamless tissue‐device integration, yet fundamental mismatches persist between the soft, hydrated nature of biological systems and the rigid, anhydrous architecture of conventional electronics, manifesting as mechanical incompatibility, electrochemical decoupling, and chronic foreign body responses. Conducting polymer hydrogels (CPHs) uniquely mediate this divide by synergizing hydrogel‐like tissue compliance and hydration with tunable mixed ionic‐electronic conductivity, enabling applications from conformal electronic skins to implantable biosensors. While CPHs have demonstrated progress in reducing interfacial impedance and mechanical mismatch, the field lacks systematic frameworks correlating molecular design with dynamic performance under physiological loading. This review consolidates advances in CPH engineering, from foundational structure‐property relationships to scalable fabrication techniques like 3D printing and photolithography, while critically evaluating emerging applications in closed‐loop theranostics and highlighting unmet challenges in long‐term stability and multimodal signal fidelity. By bridging materials innovation with clinical translation paradigms, the analysis provides a roadmap for next‐generation bioelectronics that harmonize with living systems across spatiotemporal scales.