Researchers at the University of Glasgow have developed a new form of high-resolution 'printing,' which they claim could be used to stop counterfeiting of banknotes. The new technique, as per scientists, could also find its application in storing a large amount of digital data with complete ease.

Nanoscale plasmonic color filters

Researchers reveal that they have developed nanoscale plasmonic color filters that are capable of exhibiting different colors. The colors displayed depend on the direction/orientation of the light that hits these filters.

This means one can print two detailed but different images of the same object within the same surface area.

Instead of using pigments and dyes to render colors, this technique uses structured nanomaterials that enable printing ultra high-res images with a resolution of about 100,000 DPI (100,000 colored dots per inch) or more. In comparison, a typical image found in a book or magazine usually has a maximum resolution of about 300 DPI.

Another big advantage of this newly developed nanotechnology printing is that the quality of images doesn’t degrade over time.

Demonstration of the technology

The researchers demonstrated their technology by creating different microscopic images of the Glasgow University's tower, featuring colors depending on light orientation.

Dr. Alasdair Clark, a lecturer at Glasgow University and the lead researcher of the study explains that his team created color pixels using small indents on a small piece of aluminum film and found that the colors displayed by these indents were polarization-dependent. This has enabled researchers to encode two colors into a single pixel.

High volume of data

Clark says it is possible to create a variety of colors at very high resolutions by changing the shape and size of the nanoscale. Moreover, this technique can also be used to store a large amount of digital data—about 1.46 GB/sq cm, which means one A4 sheet can easily store over 900 GB of data. Clark also suggests its use in stopping counterfeiting of banknotes because creating plasmonic colors is a complex process, and almost impossible to imitate without dedicated facilities.

This research was supported by the Physical Sciences Research Council and the Royal Academy of Engineering.

The detailed findings of the study were published in the journal, Advanced Functional Materials.