Bioinspired Unclonable 2D Photonic Crystal Patterns with Multimode Reversible Switching for Anticounterfeiting...

Area of Science:

• Materials Science
• Optics
• Nanotechnology

Background:

• Growing demand for information security and product authentication challenges existing anticounterfeiting technologies.
• Photonic crystal (PC)-based optical methods offer dynamic color regulation but face limitations in replication susceptibility and material fatigue.

Purpose of the Study:

• To develop an advanced, highly secure anticounterfeiting system inspired by natural patterns.
• To overcome the limitations of current PC-based anticounterfeiting technologies.

Main Methods:

• Fabrication of a two-dimensional (2D) PC system using nanospheres of varying sizes within a polymer matrix (polyethylene glycol diacrylate 200-vinyl methacrylate).
• Integration of concentric periodic structures to mimic tree rings.
• In situ pattern formation using controlled injection and Marangoni effects.

Main Results:

• Achieved inherently random and irreplicable "tree-ring" patterns, providing "unclonable" security features.
• Demonstrated multi-color-switching capabilities through different wetting modes (full immersion and unilateral wetting).
• Exhibited brilliant, angle-dependent structural colors without requiring responsive substrates.

Conclusions:

• The proposed 2D PC system offers a robust and simplified fabrication strategy for advanced anticounterfeiting.
• The "unclonable" nature and dynamic color switching enhance verification reliability for product authentication.