High-Resolution Total Internal Reflection-Based Structural Coloration by Electrohydrodynamic Jet Printing of Transparent Polyethylene Glycol Microdomes

Total internal reflection (TIR)-based
structural coloration
is
a brilliant strategy to overcome the need for periodic nanostructures
and complex fabrication processes. Light entering the microdome structure
undergoes TIR, and owing to varying reflection paths, it exhibits
a color that changes with the microdome size. Although solution-based
printing techniques have been proposed to achieve this effect, they
fall short of full-color realization owing to resolution limitations.
Herein, we achieved 3628 dpi of full-color and high-resolution structural
color images by printing transparent microdome structures with 1.2–9.9
μm diameter using electrohydrodynamic (EHD) jet printing. Additionally,
high-resolution EHD jet-printed structural color images display complex
encoded information, enhancing the anticounterfeiting effectiveness
through their fabrication simplicity and precise control over the
microdome size. Because of these advantages, this TIR-based structural
coloration technique with EHD jet printing is highly suitable for
anticounterfeiting applications.