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.