Heterogeneous Film Array Fabrication via Overlapping Photolithography for Dynamic Structural Coloration

Structural coloration achieved through thin films with elastomeric substrates and active materials enables color variations in response to stimuli such as bending or heat. However, complex interactions make generating unique colors from a single stimulus challenging, particularly in microscale pixel arrays. A novel two-step photo-cross-linking technique addresses this issue by utilizing ultraviolet-curable chitosan (UVCC) on polydimethylsiloxane (PDMS) to create reversible wrinkles of varying sizes related to bending. Mimicking Korean Dancheong paintings, this method generates recognizable structural colors, showing promise for anti-counterfeiting and security printing applications.