Anticounterfeiting tags based on randomly oriented MoSx clusters enabled by capillary and Marangoni flow

Recent advances in anticounterfeiting technology highlight the importance of functional materials with innovative processing methods for achieving robust anticounterfeiting tags. Here, we report a fabrication approach that enables the formation of randomly oriented MoSx or MoOx clusters of unpredictable shapes for use as anticounterfeiting tags. We exploit the combined effects of capillary and Marangoni flows to drive solute in a pre-deposited wet film that produces random clusters. The tags are read using high-speed confocal laser microscopy to extract complex topographies within seconds. Digitization converts height profiles into grayscale images, followed by mathematical processing and von Neumann debiasing to generate keys. The extracted keys are evaluated with NIST statistical tests (six tests) to confirm randomness. This approach underscores the role of functional materials and processing in robust tagging.