Bioinspired and Sustainable Physical Unclonable Functions with Antibacterial Microstructures

This study develops an eco‐friendly physical unclonable function (PUF) that integrates water and environmentally sustainable materials through a streamlined fabrication process, drawing inspiration from natural self‐assembly mechanisms. The HECTA PUF, composed of hydroxyethyl cellulose (HEC) and tannic acid (TA), spontaneously forms unique random structures through hydrogen bonding, mimicking biological randomness found in nature. The performance analysis of the HECTA PUF reveals ideal values in randomness, uniqueness, and robustness, demonstrating its potential as a highly reliable and unclonable next‐generation security solution. The HECTA PUF exhibits excellent structural reproducibility, spontaneously reforming its structures even after five reuse cycles, confirming its reusability as a sustainable film. This enhanced reusability underscores its potential for integration into bioinspired security systems within the emerging metaverse, where authentication mechanisms must align with sustainability and digital–physical convergence. Furthermore, the HECTA PUF exhibits antibacterial properties, reducing the growth of Escherichia coli by ≈87% and enhancing its applicability in safeguarding biometric data and counterfeit‐sensitive products.