Functional Micro-Defect Modified Plasma-Induced Physical Unclonable Function Wrinkle Labels Exhibiting Dual-Mode Luminescence and Angle-Tunable Structural Colors
Counterfeit products have become widespread, necessitating advanced anti-counterfeiting solutions. Inspired by random wrinkles on peanut surfaces, we propose a biologically physical unclonable function (PUF) label with all-optical anti-counterfeiting. Using spatially selective plasma etching, a single-material random wrinkling strategy overcomes limitations of traditional double-layer wrinkling, such as low entropy and complex processes, enabling selective wrinkling in fixed areas. Innovative introduction of dual-modal luminescent micron defects in polydimethylsiloxane (PDMS) films enables orthogonal control and coordination of the frequency domain of unpredictable wrinkles at the mesoscopic scale, promoting transition from long-range anisotropy to short-range isotropy. Verification requires only simple optical equipment, providing cost-effectiveness and ease of detection. This anti-counterfeiting system incorporates three collaborative security mechanisms: (i) high-entropy PUF encoded wrinkle fingerprints, (ii) angle-sensitive Bragg-like structural colors, and (iii) spatially segmented dual-mode fluorescence. The label exhibits near-ideal cryptographic properties: uniformity close to 0.5, Shannon entropy close to 1, Hamming distance approximately 0.5, and robust environmental stability (similarity >84% after storage at 2°C and 50°C for 48 h). Plasma parameter modulation enables continuous tuning of wrinkle wavelength from 6.1 to 25.0 μm. The system's straightforward preparation, portable verification, and anti-spoofing capabilities position it for real-world applications in secure packaging, high-value product labels, and smart encryption, with potential extension to flexible electronics and wearable security systems.