'Paintings' thinner than human hair: Art created using breakthrough material that could pave way for ultra-thin flexible screens

They look good enough to hang in a gallery, but each of these stunning images is smaller than the width of a human hair, the Daily Mail reports. 

Scientists created them using a breakthrough imaging technique that ‘draws’ pictures on materials using particles and atoms.

As well as being beautiful images, they are extremely high-resolution and could pave the way for ultra-thin flexible displays.

The system relies on ‘nano-pixels’ just 300 nanometres across that can be electrically turned on or off to create a mosaic of coloured dots on a display.

By comparison, the width of a human hair is approximately 80,000 to 100,000 nanometres wide.

This is done by sending tiny currents through layers of ‘phase changing’ material, that can switch from a flowing to a crystalline state.

The discovery makes it possible to create images just a few hundred nanometres across.

By creating such tiny pixels, this means images could be shown on extremely high-resolution and low-energy thin, flexible displays.

Such displays could be used in smart glasses, synthetic retinas, and foldable screens.

'We didn't set out to invent a new kind of display,' said Professor Harish Bhaskaran of Oxford University's Department of Materials, who led the research.

'We were exploring the relationship between the electrical and optical properties of phase change materials and then had the idea of creating this 'sandwich' made up of layers just a few nanometres thick.

‘We found that not only were we able to create images in the stack but, to our surprise, thinner layers of GST actually gave us better contrast.

‘We also discovered that altering the size of the bottom electrode layer enabled us to change the colour of the image.'

Although the work is still in its early stages, the Oxford team has filed a patent on the discovery with the help of Isis Innovation, Oxford University's technology commercialisation company.

Isis is now discussing the displays with companies who are interested in assessing the technology, and with investors.

The layers of the GST sandwich are created using a sputtering technique where high energy particles are fired on the material at a certain point.

These atoms are then transferred onto another material as a thin film.

The phase change material used was the alloy Ge2Sb2Te5 (Germanium-Antimony-Tellurium or GST) sandwiched between electrode layers made of indium tin oxide (ITO).

'Because the layers that make up our devices can be deposited as thin films they can be incorporated into very thin flexible materials – we have already demonstrated that the technique works on flexible Mylar sheets around 200 nanometres thick,' said Professor Bhaskaran.

'This makes them potentially useful for 'smart' glasses, foldable screens, windshield displays, and even synthetic retinas that mimic the abilities of photoreceptor cells in the human eye.'

Professor Peiman Hosseini of Oxford University's Department of Materials said: 'Our models are so good at predicting the experiment that we can tune our prototype 'pixels' to create any colour we want – including the primary colours needed for a display.

‘One of the advantages of our design is that, unlike most conventional LCD screens, there would be no need to constantly refresh all pixels, you would only have to refresh those pixels that actually change - static pixels remain as they were.

‘This means that any display based on this technology would have extremely low energy consumption.'

The research suggests that flexible paper-thin displays based on the technology could have the capacity to switch between a power-saving 'colour e-reader mode', and a backlit display capable of showing video. Such displays could also be created using cheap materials.

Co-author Professor David Wright of the Department of Engineering at the University of Exeter added: 'Along with many other researchers around the world we have been looking into the use of these GST materials for memory applications for many years, but no one before thought of combining their electrical and optical functionality to provide entirely new kinds of high-resolution, electronic colour displays – so our work is a real breakthrough.'