By providing non‐reproducible technological features, nanotechnology based developments are expected to offer a significant move forward in preventing illicit copying intellectual properties and products. Ultimately, the implementation of the novel techniques will considerably reduce tax revenue losses through counterfeiting and improve citizens’ safety and quality of life.
Holograms, tamper‐evident closures, tags and markings and RFID labels are the most widely known anti‐counterfeiting technologies. The key limitation of these methods is that they can be copied. Innovations exploiting the intrinsic nature of nano materials to give items complex and unique ‘fingerprints’ results both in the development of new approaches and improvement of existing techniques.
Holography ‐ easily identifiable holograms, for example, showing the manufacturer’s logo are primarily used as first level identification devices. Two dimensional nano scale gratings, photopolymers and luminescent nano particles can be utilized to provide an additional level of security for the holograms.
Laser surface authentication ‐ a laser is used to examine the surface roughness of an object. Complexity and uniqueness of the surface roughness code is similar to iris scans and fingerprints. The advantages of the technique is that surface roughness at nanoscale cannot be replicated. Therefore,a much higher level of security is offered to products as compared to holograms and watermarks.
Radio frequency identification (RFID) ‐ is a form of automatic identification and data capture technology where data stored on a tag is transferred via a radio frequency link. An RFID reader is used to extract this data from tags. New developments exploit nanoscale variations, naturally produced during the manufacturing process of RFIDs that are unique to individual integrated circuits , which can be verified during data transfer. This is known as the Physically Uncloneable Function (PUF).
Nano barcodes ‐ three dimensional polymer patterns on the order of tens of nanometres can be made on silicon substrates to provide 3D nanoscale data encryption key, similar to barcodes. The advantages over conventional barcode/marking are difficulty of detecting presence (covert marking)and duplication. These can be applied to banknotes,security papers, art, jewellery and gemstones.
SERS and quantum dots tags – metal nano particles produce unique electromagnetic spectra (known as surface enhanced raman scattering) while certain semiconductor nano particles (known as quantum dots) have different fluorescence based on size and chemical composition. Both can be exploited as identification tools. They offer difficulty in reproducing due to infinite combinations, covert security feature, non‐toxicity and multi functionality. These nano scaled tags can be applied in inks, adhesives, laminates, paper, packaging, textiles, glass, and others.
Nano composite tags – consist of a materials‐based pattern (with magnetic and/or optical features) that forms part of a label, tag or embedded portion of an item. The nanometre sized magnetic and optical features are generated randomly during manufacturing, constituting a unique ‘fingerprint’ that is read and stored in a central database . The result is a secure identity for an individual item that is prohibitively expensive and difficult to copy. This technology can be applied in the pharmaceutical, spare parts, fashion and food and beverage industries. Incorporating encapsulated and functionalized (e.g. thermochromic) nano particles in labels is another promising solution based on the use of nano composites.