Electrochemistry‐Enabled Optical and Plasmonic Programmable Metasurfaces

Organizing metallic nanoparticles (NPs) into well‐defined arrays enables the design of complex, collective plasmon responses. In periodic lattices with controlled spacing, the plasmon modes of individual NPs can couple with the diffraction modes of the arrays, giving rise to lattice‐plasmon resonances. By controlling the geometry of the NP arrangement, the optical, electromagnetic, and chemical properties of the system can be precisely engineered, opening pathways to advanced technologies in electronics, optics, sensing, and catalysis. However, achieving such architectures over large areas while maintaining precise control over composition and morphology remains challenging. Electrochemically fabricated metasurfaces offer a complementary bottom‐up alternative to top‐down patterning, providing direct control over material composition and morphology through low‐cost processing. This Perspective discusses how techniques such as templated electrodeposition, in situ redox patterning, and electrochemical growth and dissolution enable the formation of subwavelength architectures with tunable functionalities, typically associated with more complex fabrication routes. Despite notable advances, the link between electrochemical growth mechanisms and the design of functional optical and plasmonic arrays remains fragmented across the literature. This Perspective synthesizes these developments, clarifies the advantages and current limitations of electrochemical approaches, and outlines emerging opportunities for scalable, electrochemistry‐enabled design of functional metasurfaces.