Anti-counterfeiting in the electrical and digital industries
Smart fireproof ID taggants: Postmortem anti-counterfeiting tags authenticate marked products even after a fire incident
Sustainable electrification of mobility as well as digitalization and automation of manufacturing processes are hot topics of the highest social relevance. Globally interconnected and non-transparent trade flows along with resource scarcity and current supply chain difficulties in the semiconductor industry are truly fueling the spread of counterfeited electronics. These are often of poor quality, seldom meet local safety standards, and therefore exhibit considerable safety-relevant malfunctions. In worst case, overheating can cause a fire or explosion. Since manufacturers are liable for such damages, they are confronted not only with incalculable financial losses but also with serious reputational damage if they cannot prove forgery. This can have devastating consequences for the progress of important, cutting-edge innovations.
Analysis methods for the characterization of fire residues used in forensics are only suitable for determining the material composition, and common anti-counterfeiting tags such as QR codes or RFID chips do not withstand the flames. The vast majority of material-based marking technologies are based on either organic or metallic materials that would thermally decompose or oxidize in the event of a fire and lose their signaling properties. Only inorganic lanthanide-doped nano phosphor materials can withstand harsh fire conditions without losing their luminescent properties. However, even from this class of materials, no developed fire-resistant post-mortem marking system has emerged yet, since fire residues completely absorb light emissions to be detected.
Prof. Dr. Karl Mandel (Professorship for Inorganic chemistry) and his research group succeeded in producing material-based particulate markers whose signaling properties could withstand fire conditions and enable post-mortem authentication after a fire event. The results of this work were published in the journal Advanced Optical Materials (https://onlinelibrary.wiley.com/doi/10.1002/adom.202201642 ). The research was funded by the German Federal Ministry of Education and Research (BMBF) as part of the NanoMatFutur project Nano-ID (Grant No. 03XP0149).
The phoenix rising from the ashes
According to a modular approach, a wide variety of nanoparticulate building blocks can be assembled into hierarchically structured, so-called supraparticles using spray-drying. This flexible and scalable process is excellently suited for the generation of spherical micron-sized entities that exhibit a complex, and precisely tunable nanoarchitecture, ultimately yielding a functional material.
“The flexibility of the synthesis process allows to precisely tune the supraparticle architecture so that different, even opposing, physical properties complement each other in a way to create hybrid functional materials that offer applications for yet unsolved problems”, says Franziska Miller.
While the luminescent subunits provide a ratiometric ID fingerprint by encoding information based on relative emission intensity ratios, these hybrid particles can be simultaneously separated and purified from post-fire residues thanks to their magnetic properties. Targeted variation of Eu3+ and Tb3+ containing nanoparticle amount ratios in the supraparticle compound yields a variety of uniquely distinguishable ID fingerprints. The magnetically recovered particles are then subjected to a thermal activation step, thereby thermally decomposing molecular absorbing pyrolysis products while enabling spectral signal detection of the characteristic luminescence ID fingerprint. It was shown that these smart additives can be easily incorporated into various coatings, and thus one could superficially mark electronic components. Depending on the physical properties of this binder, marking can also be realized during the lifetime of the marked product, or the ID can be specifically hidden initially and activated once a fire has occurred.
After a real fire scenario has taken place, a publicly appointed expert could easily magnetically extract marker particles from the fire location and analyze them with fluorescence spectroscopy according to a standardized procedure to read out an ID fingerprint and thus prove the originality of a product.
Prof. Dr. Karl Mandel