Nano Argovia projects – Foldable and rollable in the future

In the Nano Argovia project META-DISPLAYS, scientists are developing a component for rollable and foldable displays that will specifically alter and control the propagation of light. This “metasurface phase retarder” must be color-neutral and allow good transmission of light — although it should also reduce back reflections and thereby maximize contrast. Above all, it must be extremely thin so that the screen remains highly flexible.

In the future, greater use will be made of flexible screens. (Image: Rolic Technologies)

Various requirements
In the future, there will be an increasing number of foldable and rollable screens, tablets and smartphones. To ensure high flexibility, the components incorporated into these devices need to be thinner than their conventional counterparts. It is also necessary to reduce the back reflection of ambient light in order to maximize display contrast.

To this end, researchers from CSEM Muttenz, the Paul Scherrer Institute PSI and Rolic Technologies Ltd. are participating in the Nano Argovia project META-DISPLAYS with a view to developing a “metasurface phase retarder” that — in combination with a polarizer — will meet these conditions while remaining highly transparent.

Promising structured surfaces
A metasurface phase retarder has tiny, nanoscale structures on its surface that enable highly effective control of the phases of an electromagnetic field emitted by a light source. Using state-of-the-art lithographic methods, it’s possible to structure the surfaces of these phase retarders in different ways to achieve the necessary high level of phase retardation of light passing through a layer with a thickness of only a few hundred nanometers.

Led by Dr. Benjamin Gallinet (CSEM), the team will test different surface nanostructures with a view to identifying a combination that can reduce the thickness of the phase retarder while achieving high transmission and color neutrality. For this, the researchers are using nanotechnology-based lithography methods (ultraviolet nanoimprint lithography) that can also be applied on an industrial scale.

“A metasurface device will enable Rolic to strengthen its competitive advantage as a material supplier to the display industry. In addition, metasurface technology has great potential in other segments of consumer electronics — for example, as flat screen elements in smartphones.”

Dr. Richard Frantz, Head of Development, Rolic Technologies Ltd.

Further information:

Nano Argovia program
www.nanoargovia.swiss

Rolic Technologies Ltd.
https://on.basf.com/3xtllYA

CSEM
https://www.csem.ch/Home

Paul Scherrer Institute
https://www.psi.ch/en