Multi-stimuli-responsive phase change hydrogels with dynamic fluorescence chromism based on AIE hydrophobic carbon dots for advanced encryption

• • The hydrogel exhibits a tensile modulus swing from 6.28 MPa (molten) to 36.23 MPa (crystalline), enabling mechanically tunable matrices for adaptive device integration. • • Light transmittance switches between 42% and 87% across the phase transition, providing an optical readout for encryption states. • • After five consecutive shape-memory cycles, the recovery ratio (Rr) and fixity ratio (Rf) remain above 96%, confirming durability for repeated use in anti-counterfeiting labels. • • Solvent exchange triggers fluorescence color shift from blue to red, enabling multi-level optical encryption beyond single-wavelength systems.