Enabling Single-Challenge Multichannel-Response OPUFs: Adaptive Nanofilms from Aggregation-Controlled Multicolor...

Area of Science:

• Materials Science
• Optics
• Nanotechnology

Background:

• Optical physical unclonable functions (OPUFs) are crucial for anti-counterfeiting but face challenges in multichannel unclonability, scalability, and non-destructive application.
• Existing OPUF technologies struggle to balance these critical performance metrics.

Purpose of the Study:

• To engineer a single-challenge, multichannel-response OPUF label with hierarchical disorder.
• To achieve high unclonability, scalability, and non-destructive implementation for advanced anti-counterfeiting and secure data storage.

Main Methods:

• Fabrication of carbon dots with controlled aggregation states (highly vs. weakly aggregated) via surface functional group ratios.
• Engineering sub-nanoscale fractal structures and micro-nano architectures through spontaneous aggregation and random assembly/printing.
• Integration of the OPUF label into protective coatings for non-destructive application, demonstrated on butterfly specimens.

Main Results:

• Achieved sub-nanoscale fractal structures and irreproducible micro-nano architectures for inherent randomness and anti-duplication.
• Validated an ultrahigh theoretical encoding capacity of approximately 2.04 × 10^90.
• Demonstrated a single 5 µm label generating three independent keys (bright-field, green, red channels) with high bit uniformity and low error rates.

Conclusions:

• The developed OPUF label effectively balances multichannel unclonability, scalability, and non-destructive implementation.
• The technology provides an "invisible armor" with broad applications in secure data storage and high-precision anti-counterfeiting.
• Hierarchical disorder engineering is a promising strategy for next-generation OPUFs.