Programmable Invisible Photonic Patterns with Rapid Response Based on Two-Dimensional Colloidal Crystals

The development of invisible patterns via programmable patterning can lead to promising applications in optical encryption. This study reports a facile method for building responsive photonic crystal patterns. Commercially printed patterns were used as a mask to induce invisible patterns revealed by wetting. The masked areas exhibit different swelling kinetics, leading to strong structural colors in the masked area and transparent features in the unmasked area. The contrast could disappear through different wetting behavior, providing a unique and reversible wetting feature. This programmable printing is expected to become an environmentally friendly technique for scalable invisible optical anti-counterfeiting technology.

Automated summary

A facile method for building responsive photonic crystal patterns was developed, utilizing commercially printed patterns as masks to induce invisible patterns through wetting. The masked areas exhibit strong structural colors while the unmasked areas remain transparent, providing a unique and reversible wetting feature. This programmable printing technique is expected to be an environmentally friendly approach for scalable invisible optical anti-counterfeiting technology.