A research team from the Singapore University of Technology and Design have created a new Holographic Colour Printing method useful for counterfeit deterrence.
Previously on FMS Blog, we’ve covered how printing technology may be able to prevent counterfeiting and a breakthrough that was made in helping to counter counterfeit currency printing. But extensive research from a team at the Singapore University of Technology and Design could prove to be just as, if not more significant. Their invention is a new type of anti-counterfeiting device which they have been using as a deterrent to identify forged or fraudulent cards, documents and banknotes.
Holographic Colour Printing
The method creates what the team remark as “holographic colour prints”. The prints are generated by an optical device, which at first appears in regular colour print when put under white light. However, when laser pointers are used directly onto the print, it projects up to three different images onto a distant screen set up by the team. A key different between the holographs produced by the device are that they don’t contain a ‘frosted-glass’ style of appearance. Instead, it can produce several images and a variation of colours. This reaction is created by Nano 3D printed polymer structures which makes it capable to be used as a form of optical document security.
To explain this further, Associate Professor Joel Yang comments that colour pixels within the device have been created by overlaying structural coloured filters onto phase plates. This was then developed inline with a computer algorithm produced by the research team which was able to take multiple images as it’s main input. The generated output file was then able to determine the positions of different phase and coloured filter elements.
To sculpt the holographic print, the team used a nanoscale 3D printer. They then used varying thicknesses of polymerized cuboids to act as the phase plates and to form three separate holograms. In order to make these stand out and evidence how the method could be used to deter counterfeiting, the holograms were adjusted to project a red thumbprint, a green key image and blue lettering reading as “SECURITY”. All of these elements were embedded into one final output that would show when the print was exposed to laser pointers.
Improving Technology to Deter Counterfeiters
Leader of the project and Associate Professor at the Singapore University of Technology and Design, Joel Yang expresses how the holographic colour printing method could improve the technology required to identify and stop counterfeiting.
“The relationship of holograms in combating counterfeiting is analogous to antibiotics against infections. Every so often, new technology is needed to deter counterfeiters as the old-fashioned holograms become easier to copy. For the first time, multiple holograms that are colour selective are ‘woven’ into a colourful image using advanced nanofabrication techniques. We are hopeful that these new holographic colour prints are user friendly but counterfeit unfriendly: They are readily verified but challenging to copy, and can provide enhanced security in anti-counterfeiting applications.”
Science Daily – Holographic colour print for optical security