Multifunctional Hydrogel Materials for Advanced Neural Interfaces

Conventional rigid neural electrodes mismatch the soft, wet nature of neural tissue, hindering long‐term stable interfaces. Multifunctional hydrogels, with their tissue‐like compliance, ionic conductivity, and biocompatibility, offer a promising solution to bridge bioelectronic systems and neural tissues. This review systematically examines critical hydrogel properties—mechanical compliance, adhesion, biocompatibility, conductivity, and injectability—for neural interfacing. It summarizes recent advances in hydrogel‐based technologies, including hydrogel coatings, conductive hydrogel electrodes, and integrated hydrogel electronics. Future challenges involve balancing biodegradation with long‐term stability, developing advanced fabrication strategies, and ensuring chronic performance stability. Key future directions include optimizing hydrogel properties for chronic applications, creating smart‐responsive hydrogels, integrating artificial intelligence, and advancing wireless systems. Leveraging materials science, bioengineering, and nanotechnology, hydrogel‐based neural interfaces are poised to unlock unprecedented capabilities in brain‐computer interfaces, neural prosthetics, neuromodulation, and regenerative therapies, heralding a paradigm shift in neurotechnology.