Integrated Hydrogel Optical Fiber Electronics with Mechanically Robust Interfaces Enable Simultaneous Electrophysiological Recording and Optogenetic Modulation

Abstract

Abstract Hydrogel‐based electrodes and optical guides are promising tools for neural bioelectronics, offering tissue‐like compliance, hydration capacity, and customizable functionalities. However, integrating multiple hydrogel modalities into a single device remains challenging due to material compatibility, cross‐modal interference, and interfacial integration issues. In this work, an integrated hydrogel optical fiber electronics (iHOFE) platform is reported, including a step‐index optical core, a conductive hydrogel layer, and a tissue‐matched insulating sheath. By engineering the robust interface between each layer through chemical bonding and topological entanglement, a multilayer architecture capable of concurrent electrical and optical operation under dynamic mechanical deformation is created, thus high‐fidelity electrophysiological recording and optogenetic modulation within the same region. The efficacy of the iHOFE is validated via two‐month hippocampal implantation, demonstrating recording and manipulation of neural activity. This platform marks a significant advancement in developing multifunctional neural bioelectronics for interrogating and manipulating deep neural circuits compared to existing technologies.