New technology can print images without ink

A team of scientists, including one of Indian-origin, have created the highest possible resolution images — about 1,00,000 dots per inch in full colour without ink or dyes which can potentially revolutionise the way images are printed.

Researchers from Institute of Materials Research and Engineering (IMRE) in Singapore have demonstrated an innovative method for producing sharp, full-spectrum colour images at 1,00,000 dots per inch (dpi) which can be applicable in reflective colour displays, anti-counterfeiting, and high-density optical data recording.

In comparison, current industrial printers such as inkjet and laserjet can only achieve up to 10,000 dpi while research grade methods are able to dispense dyes for only single colour images.

This technique allows colouring to be treated not as an inking matter but as a lithographic matter, which can potentially revolutionise the way images are printed and further developed for use in high-resolution reflective colour displays as well as high density optical data storage.

Researchers created sharp, full-spectrum colour images using metal-laced nanometer-sized structures, without the need for inks or dyes. 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. Using a similar concept with the help of modern nanotechnology tools, the 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 Dr Karthik Kumar, one of the key researchers involved.

“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,” Kumar said in a statement.

“Instead of using different dyes for different colours, we encoded colour information into the size and position of tiny metal disks. These disks then interacted with light through the phenomenon of plasmon resonances,” said Dr Joel Yang, the project leader of the research.