Ionic–Bionic Interfaces: Advancing Iontronic Strategies for Bioelectronic Sensing and Therapy

Iontronic bioelectronics provides a powerful framework for bridging the mismatch between conventional electronic systems and soft, ion‐mediated biological tissues. By harnessing mobile ions as charge carriers and functional mediators, iontronic devices enable biocompatible, conformal, and low‐impedance interfaces that support both signal acquisition and therapeutic delivery. Recent advances in ionic materials, such as hydrogels, ion gels, and ionic liquids, have facilitated high‐fidelity physiological sensing, wound monitoring, and programmable drug and ion release. In addition to passive sensing and delivery, emerging iontronic platforms integrate real‐time biosignal monitoring with adaptive, AI‐guided feedback to enable closed‐loop therapeutic control. This review highlights the multifunctional role of ions in sensing, modulation, and stimulation across diverse applications, including skin‐interfaced electronics, neural and cardiac interfaces, and wound therapy. Key challenges such as operational stability, signal specificity, and long‐term biocompatibility are further examined, and material, structural, and system‐level innovations that are paving the way toward intelligent, responsive, and clinically viable iontronic bioelectronic platforms are discussed.