Multifunctional Rare‐Earth Doped Hydrogels With Self‐Healing, Strong Adhesion, and Tunable Fluorescence Properties

Abstract Smart hydrogels that combine mechanical resilience with dynamic optical functionality remain a critical unmet challenge in materials science. Luminescent hydrogels with tunable optical properties have garnered significant attention due to their potential applications in bioimaging, anti‐counterfeiting, and flexible electronics. In this study, we present a novel luminescent hydrogel system by incorporating lanthanide (Eu 3+ and Tb 3+ ) pyridine‐2,6‐dicarboxylic acid (PDA) complexes into a polyacrylamide (PAM) network. The resulting hydrogels exhibit unprecedented mechanical robustness, while maintaining photoluminescence. Crucially, these materials demonstrate dual‐programmable emission: excitation wavelength (254/365 nm) and hydration state (wet/dry) independently regulate chromatic output. This work provides a conceptual framework for decoupling mechanical and optical properties in soft matter, opening avenues for intelligent materials in anti‐counterfeiting, adaptive biosensing, and energy‐efficient optoelectronics.