Bioinspired Deformable Antireflective Materials by Block Copolymer Self-Assembly.

Antireflective surface is a crucial component for high-performance photonic systems but has been principally focused on hard, flat device geometry. We present an antireflective strategy for deformable device geometry that combines superior optical performance with mechanical robustness. Bioinspired nanohole arrays are embedded into a transparent polymer layer by exploiting block copolymer self-assembly. The resultant nanoengineered surface reduces light reflection by over 70% across the visible spectrum compared to a nonpatterned surface, owing to gradual refractive index along nanohole geometry that mediates optical impedance mismatch with the air interface, as supported by simulation studies. Adoption of interconnected nanostructures facilitates efficient dissipation of external mechanical stress, ensuring high mechanical resilience, even under repeated nonlinear deformation cycles. Furthermore, multifunctionality with self-cleaning capabilities is demonstrated, attributed to genuine hydrophobicity of nanostructured geometry. Our straightforward strategy delivers a promising solution for next-generation optical and optoelectronic systems commonly involved in complex and deformable design configurations.