Hydrogel-based sensors for multimodal health monitoring: from material design to intelligent sensing

triboelectric nanogenerators for autonomous operation; (2) closed-loop diagnosis-therapy platforms; and (3) artificial intelligence (AI) for advanced signal interpretation and diagnostics. These improvements enable applications in epidermal electronics, smart bandages, and implantable devices. Despite their progress, challenges remain in the environmental stability, integrated multimodal sensing, and clinical translation of implantable systems. Addressing these issues requires interdisciplinary collaboration to advance hydrogel platforms toward autonomous, personalized, and precision medicine.