Programmable Self‐Regulation with Wrinkled Hydrogels and Plasmonic Nanoparticle Lattices

This paper describes a self‐regulating system that combines wrinkle‐patterned hydrogels with plasmonic nanoparticle (NP) lattices. In the feedback loop, the wrinkle patterns flatten in response to moisture, which then allows light to reach the NP lattice on the bottom layer. Upon light absorption, the NP lattice produces a photothermal effect that dries the hydrogel, and the system then returns to the initial wrinkled configuration. The timescale of this regulatory cycle can be programmed by tuning the degree of photothermal heating by NP size and substrate material. Time‐dependent finite element analysis reveals the thermal and mechanical mechanisms of wrinkle formation. This self‐regulating system couples morphological, optical, and thermo‐mechanical properties of different materials components and offers promising design principles for future smart systems. A self‐regulating platform combining hydrogel microwrinkles and plasmonic nanoparticle lattices can demonstrate programmable regulation with tunable timescales. The system couples the dynamic optical properties of the wrinkle patterns with moisture‐responsive mechanical actuation that can be controlled by the photothermal effect of the plasmonic lattices.