Direct Writing Unclonable Watermarks with an Electrochemical Jet

Speidel, Alistair; Bisterov, Ivan; Clare, Adam Thomas

Abstract

Counterfeit parts result in significant losses per annum and are often dangerous, therefore they represent a serious concern for manufacturers and end users alike. Easily written but unclonable watermarks undermine the proposition of the counterfeiter. Here, a rapid electrochemical jet engraving routine is presented to encode robust materials with self-organized dendritic structures at length scales that can be imaged with a smartphone. Surface defects act as stochastically distributed seeds from which discrete pitting events can be propagated by translating the electrochemical field. While the vascular pathways can be directly written at the macro scale, the formation and propagation of microscale dendritic arms is chaotic, caused by the implicit randomness of the defect seeds and the supply of ions to the surface. The latter is confounded by random perturbations in the flow condition. Each engraved dendrite is unique, stable at high temperature (>500°C) and can be subjected to rapid image recognition to allow individual mark identification at any point during part production and delivery, or through part lifetime.

Citation

Speidel, A., Bisterov, I., & Clare, A. T. (2022). Direct Writing Unclonable Watermarks with an Electrochemical Jet. Advanced Functional Materials, 32(51), Article 2208116. https://doi.org/10.1002/adfm.202208116

• Journal Article Type: Article
• Acceptance Date: Sep 22, 2022
• Online Publication Date: Oct 4, 2022
• Publication Date: Dec 16, 2022
• Deposit Date: Dec 15, 2023
• Publicly Available Date: Dec 20, 2023
• Journal: Advanced Functional Materials
• Print ISSN: 1616-301X
• Electronic ISSN: 1616-3028
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 32
• Issue: 51
• Article Number: 2208116
• DOI: https://doi.org/10.1002/adfm.202208116
• Keywords: Electrochemistry; Condensed Matter Physics; Biomaterials; Electronic, Optical and Magnetic Materials
• Public URL: https://nottingham-repository.worktribe.com/output/12035905
• Publisher URL: https://onlinelibrary.wiley.com/doi/10.1002/adfm.202208116