According to a study conducted at the Vanderbilt University in Texas gold nano-spirals can help with protecting your identity when you handle cash or credit cards. It seems that with this new invention there is no possibility for identity theft to take place. The study was published in the Journal of Nanophotonics.
The swirls of gold are so tiny that they cannot be seen by the human eye. If they would be printed onto identity cards or currency it would be impossible to counterfeit the objects. The research was conducted by students from the university. They used the symbols which are called Archimedes spirals and with ultrafast lasers they examined their optical properties.
Roderick Davidson II a doctoral student at the Vanderbilt University developed a method to study the optical behavior of the spiral and he explained that they are tinier than any other spirals which has ever existed in the scientific literature.
If the Archimedes spirals are exposed to normal wavelengths they are invisible. They can be observed on the surface which they are imprinted only when they are exposed to infrared light.
In addition a unique response is noticed if they are exposed to polarized laser light. The nano-spiral shows blue light wavelengths which make it impossible to be counterfeited unless one has a laboratory. That is why the spirals are a signature which can be easy to customize, but impossible to counterfeit.
Since the spirals only require extremely small quantities of precious metals it is not at all expensive to produce them. Instead of gold, silver and platinum can also be used. The metals can be printed on various substrates such as paper, plastic etc. In order to prove that this works the researchers imprinted them on glass using electron-beam lithography. Since they are made using precious metals the nano-spirals can resist any kind of chemical degradation.
Professor Richard Haglund remarked:
“If nano-spirals were embedded in a credit card or identification card, they could be detected by a device comparable to a barcode reader.”
Besides being a good solution against counterfeiting and theft the spiral could also be encapsulated and introduced in substances which are closely tracked such as chemicals, explosives or drugs.
Image Source: Nature World Report