Unique patterns made from tiny, randomly scattered silver nanowires have been created by a group of researchers from South Korea in an attempt to authenticate goods and tackle the growing problem of counterfeiting.
The nanoscale 'fingerprints' are made by randomly dumping 20 to 30 individual nanowires, each with an average length of 10 to 50 µm, onto a thin plastic film, and could be used to tag a variety of goods from electronics and drugs to credit cards and bank notes.
They have been presented in a paper published today, 21 March, in IOP Publishing's journal Nanotechnology.
According to the researchers, the fingerprints are almost impossible to replicate because of the natural randomness of their creation and the difficulty associated with manipulating such small materials.
Lead author of the research Professor Hyotcherl Ihee, from the Korea Advanced Institute of Science and Technology (KAIST) and Institute for Basic Science (IBS), said: "It is nearly impossible to replicate the fingerprints due to the difficulty in trying to manipulate the tiny nanowires into a desired pattern. The cost of generating such an identical counterfeit pattern would generally be much higher than the value of the typical product being protected."
The researchers estimate that the fingerprints could be produced at a cost of less than $1 per single pattern, which was demonstrated in their study by synthesizing a solution containing individual silver nanowires, coating the nanowires with silica, doping them with specific fluorescent dyes and then randomly dropping them onto a transferable film made from flexible polyethylene terephthalate (PET).
The fluorescent dyes allowed the patterns, which are invisible to the naked eye, to be visually identified and authenticated under an optical microscope and could add another layer of complexity to the 'fingerprints' if a number of different coloured dyes are used.
The researchers believe the fingerprints could also be tagged with a unique ID, or barcode, which could facilitate a quick search in a database and ease the process of authentication or counterfeit identification.
"Once a pattern is tagged and stored on a database using a unique ID, a certain substrate, whether this is a bank note or a credit card, could be authenticated almost immediately by observing the fluorescence images and comparing it with stored images," continued Professor Ihee.
"These authentication processes can be automated by employing an algorithm that recognises the positions and colours of the silver nanowires and digitizes that information in a database. Such digitized information could significantly reduce the size of the stored data and reduce the time required for the authentication process."
According to the World Customs Organisation, around six per cent of global traded goods are counterfeit, which the researchers believe could be reduced by using their technique to authenticate goods.
"Compared to other anti-counterfeit methods, the fingerprints are cheap and simple to produce, they are extremely difficult to replicate and can be authenticated very straightforwardly," concluded Professor Ihee.
From Friday 21 March this paper can be downloaded from http://iopscience.iop.org/0957-4484/25/15/155303/article.
Notes to Editors
For further information, a full draft of the journal paper or contact with one of the researchers, contact IOP Press Officer, Michael Bishop: Tel: 0117 930 1032, E-mail: firstname.lastname@example.org
For more information on how to use the embargoed material above, please refer to our embargo policy.
IOP Publishing Journalist Area
The IOP Publishing Journalist Area gives journalists access to embargoed press releases, advanced copies of papers, supplementary images and videos. In addition to this, a weekly news digest is uploaded into the Journalist Area every Friday, highlighting a selection of newsworthy papers set to be published in the following week.
Login details also give free access to IOPscience, IOP Publishing's journal platform.
To apply for a free subscription to this service, please email Michael Bishop, IOP Press Officer, email@example.com, with your name, organisation, address and a preferred username.
Anti-counterfeit nanoscale fingerprints based on randomly distributed nanowires
The published version of the paper 'Anti-counterfeit nanoscale fingerprints based on randomly distributed nanowires' (Jangbae Kim et al 2014 Nanotechnology 25 155303) will be freely available online from 21 March 2014. It will be available at http://iopscience.iop.org/0957-4484/25/15/155303/article.
Nanotechnology encompasses the understanding of the fundamental physics, chemistry, biology and technology of nanometre-scale objects.
IOP Publishing provides a range of journals, conference proceedings, magazines, websites, books and other services that enable researchers and research organisations to achieve the biggest impact for their work.
We combine the culture of a global learned society with highly efficient and effective publishing systems and processes. We serve researchers in the physical and related sciences in all parts of the world through our offices in the UK, US, Germany, China and Japan, and staff in many other locations including Mexico and Russia.
IOP Publishing is a wholly owned subsidiary of the Institute of Physics. The Institute is a leading international scientific society with over 55 thousand members promoting physics and bringing physicists together for the benefit of all.
Surplus generated by IOP Publishing is gift aided to the Institute to support science and scientists in both the developed and developing world.
Access to Research
Access to Research is an initiative through which the UK public can gain free, walk-in access to a wide range of academic articles and research at their local library. This article is freely available through this initiative. For more information, go to http://www.accesstoresearch.org.uk.
The Institute of Physics
The Institute of Physics is a leading scientific society. We are a charitable organisation with a worldwide membership of more than 50,000, working together to advance physics education, research and application. We engage with policymakers and the general public to develop awareness and understanding of the value of physics and, through IOP Publishing, we are world leaders in professional scientific communications. Go to http://www.iop.org