Multi‐Scale Engineering of Photonic Meta‐Structures With Emergent Optical Resonances via Colloidal Crystal Engineering With DNA and Microwell Templates

ABSTRACT

Metasurfaces offer control over light–matter interactions, but their material scope is often constrained by top‐down fabrication techniques, limiting compositional flexibility in meta‐atoms and the accessible optical properties. Herein, a bottom‐up approach integrates colloidal crystal engineering with DNA with lithographically defined microwell templates to create meta‐structures composed of nanoparticle superlattices that function as programmable meta‐atoms. The microwell environment stabilizes non‐equilibrium superlattice habits inaccessible with homogeneous crystallization, decoupling habit formation from lattice symmetry. This approach enables tuning of optical response through hierarchical parameters: 1) nanoparticle composition and size, DNA length, and lattice symmetry define superlattice optical characteristics; 2) superlattice size and habit determine resonator supported modes; and 3) inter‐superlattice spacing and arrangement govern collective lattice effects. This multiscale modularity enables access to a vast combinatorial design space for optical engineering. As proof‐of‐concept, a meta‐structure comprised of periodic cylindrical superlattices exhibiting a near‐infrared Mie‐ resonance is fabricated. Despite being composed of metallic gold nanoparticles, the superlattices exhibit an emergent dielectric‐like response with low effective extinction in the NIR/mid‐IR regime, enabling volumetric electromagnetic field penetration. Field maps show resonant behavior characteristic of magnetic dipole Mie modes. By integrating colloidal assembly with system‐level optical functionality, this work establishes a bottom‐up framework for designing photonic meta‐structures.