Geometrically Programmed Wrinkle Architectonics for High Angle‐Dependent Structural Coloration

Wrinkle‐based diffraction gratings offer a scalable route to pigment‐free structural coloration, yet most platforms are limited by globally aligned, linear wrinkles that provide limited spatial programmability and narrow angular selectivity. Here, we report geometrically programmed wrinkle architectonics in a UV‐curable chitosan (UVCC)/polydimethylsiloxane (PDMS) bilayer, where lithography‐defined, “geometric voids” serve as boundary constraints and stress concentrators to deterministically steer wrinkle trajectories during mechanical deformation. Simple geometric primitives effectively reshape the local stress field through geometrically incompatible confinement, transforming 1D gratings into shape‐specific, spatially bifurcated domains characterized by curvilinear orientation and straight‐wrinkle fields. We quantify these trajectory fields using the curvature metric and map critical design levers, such as inter‐pattern spacing, UVCC thickness, and pattern asymmetry, that modulate curvature magnitude and steering range without altering diffraction periodicity. Circular perimeters sustain extended semi‐circular trajectories, whereas polygonal vertices concentrate stress to induce aggressive local curvature. This programmed orientation dramatically amplifies angular dispersion: symmetric circular arrays achieve peak viewing‐angle responsivity nearly three times higher than that of unpatterned thin films. A macaw security motif confirms wide‐angle azimuthal readability and the formation of device‐unique optical fingerprints for anti‐counterfeiting. This work transforms a ubiquitous mechanical instability into a geometry‐addressable photonic platform for high‐level authentication and advanced displays.