Innovative method prints colours without inks

Singapore, Aug 13 (IANS) An innovative method for creating sharp, full-spectrum colour images at 100,000 dots per inch (dpi) does not need inks or dyes, thanks to metal-laced nano-sized structures.

Conversely, current inkjet or laserjet printers can only achieve up to 10,000 dpi, while research grade methods are able to dispense dyes for only single colour images.

This novel breakthrough - achieved by Agency for Science, Technology and Research Institute of Materials Research and Engineering (IMRE) - allows colouring to be treated not as an inking matter but as a lithographic matter, which can potentially revolutionise the way images are printed, the journal Nature Nanotechnology reports.

The inspiration for the research was derived from stained glass, which is traditionally made by mixing tiny fragments of metal into the glass. It was found that nanoparticles from these metal fragments scattered light passing through the glass to give stained glass its colours, according to a statement from the Agency for Science.

Using a similar concept with the help of modern nanotech tools, researchers precisely patterned metal nanostructures and designed the surface to reflect the light to achieve the colour images.

"The resolution of printed colour images very much depends on the size and spacing between individual 'nanodots' of colour," explained Karthik Kumar, a key researcher.

"The closer the dots are together and because of their small size, the higher the resolution of the image. With the ability to accurately position these extremely small colour dots, we were able to demonstrate the highest theoretical print colour resolution of 100,000 dpi," added Kumar.