Direct Writing Unclonable Watermarks with an Electrochemical Jet
Direct Writing Unclonable Watermarks with an Electrochemical Jet
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DOI：
10.1002/adfm.202208116
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发表时间：
2022-10
影响因子：
19
通讯作者：
A. Speidel;Ivan Bisterov;A. Clare
中科院分区：
文献类型：
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作者：
A. Speidel;Ivan Bisterov;A. Clare
假冒零件每年都会造成重大损失，并且通常很危险，因此它们代表了制造商和最终用户的严重关注。容易编写但不可克隆的水印破坏了伪造者的主张。在这里，提出了一种快速电化学喷射雕刻程序，用于编码具有自组织树枝状结构的坚固材料，其长度尺度可以用智能手机成像。表面缺陷作为随机分布的种子，离散的点蚀事件可以通过平移电化学场来传播。虽然血管通路可以在宏观尺度上直接写入，但微观尺度树枝状臂的形成和传播是混乱的，这是由缺陷种子和向表面供应离子的隐含随机性引起的。后者是混淆的随机扰动的流动条件。每个雕刻的枝晶都是独特的，在高温（>500 °C）下稳定，并且可以进行快速图像识别，以允许在零件生产和交付期间或零件寿命期间的任何时间点进行单独标记识别。
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.