Jellyfish‐Inspired Hydrogels Enabling Synergistic Antifouling and Low‐Drift for Transformer‐Assisted Multimodal Marine Bioelectronics

Hydrogels have emerged as a versatile materials platform for soft and biointegrated electronics. However, reliable hydrogel bioelectronics under seawater conditions is limited by biofouling at interfaces, high‐salinity swelling‐induced drift, and noise‐robust temporal decoding. Here, we present a hydration‐locked percolation strategy to engineer a jellyfish‐inspired hydrogel that combines synergistic antifouling with drift‐resistant conduction for AI‐assisted multimodal marine bioelectronics. The constructed hydration‐polyphenol network suppresses nonspecific adsorption and early biofilm evolution, achieving a synergistic antifouling system that repels and inactivates fouling organisms. Meanwhile, cross‐substrate wet anchoring and localized swelling suppression stabilize electron‐percolation pathways, thereby enabling long‐term stable high conductivity (22 S m − 1 ) and physiological signal acquisition with high signal‐to‐noise ratio in seawater. Notably, a tailored multimodal decoding framework integrating Transformer encoder with multilayer perceptron further enables accurate interpretation of complex physiological signals (98.5% accuracy) by capturing long‐range temporal dependencies and cross‐modal correlations. This integration of high‐performance bioinspired hydrogels with Transformer‐assisted decoding paves the way for long‐term, high‐fidelity marine bioelectronics.