A Physical Unclonable Function Based on Recyclable Polymer Nanoparticles to Enable the Circular Economy

Abstract

The circular economy requires that we know what a product is made of, that we can control that it is not a fake, and that we know how to recycle it. This requires a digital twin of each product where the information is stored and that we can access using a smartphone. The creation of digital twins requires a connection between the physical and digital worlds, which in turn requires that all objects have a unique identifier valid in both domains. The realization of the intrinsic potential of creating digital twins of individual products that link physical and digital identities in turn requires that the physical identifier is truly unique and that it cannot be copied. Furthermore, the physical identifier should not interfere with the product lifecycle, in particular recyclability, as this would be a potential blocker in a circular economy. Here, we present a physical identifier on the basis of a physical unclonable function (PUF) made from polymer nanoparticles and imbedded in a polymer laminate, where all components can be made from the same recyclable material. Such materials are commonly used for packaging in the fragrance and cosmetics industry. The development of the PUF system is presented, and each PUF was validated using a proprietary smartphone application with a QR code as a common pattern defining the PUF canvas. The functionality of the PUF was demonstrated across product types as diverse as lateral flow assays and construction materials. We conclude that polymer nanoparticle PUFs are a viable and directly recyclable solution to document authenticity and inform on recyclability of polymers in the circular economy.

Unclonable Features via Electrospraying of Bulk Polymers

“…The capability of fabricating randomly positioned features with a broad range of sizes at different length scales is significant for PUF applications . Microscopic (>1 μm) features can be authenticated using portable cameras and even smartphones, making the technique accessible. , Nanoscopic features are suitable for high-end applications, where the authentication can be performed via advanced microscopy techniques such as SEM and atomic force microscopy (AFM) as recently demonstrated. Considering the need for infrastructure and read time, such nanoscopic features can be utilized as additional security layers for valuable products and documents.…”

“…These issues strongly motivate fabrication of PUFs using inexpensive and bulk materials. Polymers are particularly attractive materials for PUF applications not only for their low cost but also for their recyclability as effectively demonstrated in a recent study by Sørensen and co-workers . It is highly desirable to generate PUFs constructed from microscopic and nanoscopic features with complex morphology, which are fabricated in one step at room temperature from bulk and low-cost materials.…”

Molecular Nanotechnology for Tomorrow’s World: A Forum Dedicated to Professor Sir Fraser Stoddart on the Occasion of His 80th Birthday

“…The separation and degradation of targeted species by using functional nanosystems are important as we seek a sustainable future. Sørensen et al presented a physical unclonable system by using recyclable polymer nanoparticles imbedded in a polymer laminate for enabling the circular economy . Chen and co-workers fabricated nanoporous molecular crystals for the efficient separation of CO 2 /CO, where both trace (1%) and bulk (50%) amounts of CO 2 can be removed from the gas mixtures by pressure-swing adsorption .…”

Graphene-Based Physically Unclonable Functions with Dual Source of Randomness

“…Physically unclonable functions (PUFs) have recently attracted increasing attention for authentication and anticounterfeiting applications because of their unpredictable and unreproducible nature. The underlying concept of PUFs is the use of physical systems with random responses as cryptographic primitives. , Various research efforts − have been made to create PUF-based security tags that are completely immune to forgery and cloning. High encoding capacities have been attained by maximizing the spatial randomness of tag components and using multiplex encoding strategies. − Cost-effective and widely applicable fabrication processes should be further developed to realize the extensive use of such PUF-based security tags in various commercial applications.…”