Incredibly Thin Silver for Touchscreens Won’t Tarnish

Silver has long been known as the highest quality plasmonic material for visible and near-infrared applications, its usage has been limited due to practical issues of continuous thin film formation, stability, adhesion, and surface roughness. By taking advantage of it, scientists have created a thin silver film for touch screens and flexible displays.

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Incredibly Thin Silver for Touchscreens Won’t Tarnish
Image credit: Pixabay

Scientists from the University of Michigan have developed the thinnest, smoothest layer of silver for touch screens and flexible displays. This thin silver is resistant to air exposure. It could guide light about 10 times as far as other metal waveguides. The layer is even resistant to tarnishing. By creating affection through metamaterial superlenses on the transportation of information within a silicon chip, the thin silver could potentially improve computing power.

Scientists just combined the silver with a little bit of aluminum to produce this thin layer of silver. They then applied an additional anti-reflective coating over this layer. This coating makes the layer up to 92.4 percent transparent.

Scientists next layered the silver films into a metamaterial hyperlens. These hyperlenses are responsible create dense patterns with feature sizes.

Professor L. Jay Guo said, “Screens of all stripes need transparent electrodes to control which pixels light up, but touchscreens are particularly dependent on them. A modern touch screen is made of a transparent conductive layer covered with a nonconductive layer. It senses electrical changes where a conductive object—such as a finger—is pressed against the screen.”

“The transparent conductor market has been dominated to this day by one single material. This material, indium tin oxide, is projected to become expensive as demand for touch screens continues to grow; there are relatively few known sources of indium. Before, it was very cheap. Now, the price is rising sharply.”

Generally, it is difficult to create a continuous layer of silver that is less than 15 nanometers thick. But, silver has the capability that assembles in small islands rather than extend into an even coating. The most fascinating that this thin silver is less than 7 nanometers thick. When they exposed it to air, it didn’t immediately tarnish as pure silver films do. Even after a long duration, the film maintains its conductive properties and transparency.

These thin silver films offer two more tricks. Both tricks need to transport visible and infrared light waves along its surface. The light waves shrink and travel, shows oscillations in the concentration of electrons on the silver’s surface.

These oscillations create the frequency of the light and preserve it so that it could be used on the other side.

The plasmonic capability of this silver film can also be harnessed in metamaterials. This controls light in ways that break the usual rules of optics.

Cheng Zhang, a recent doctoral graduate in electrical engineering and computer science said, “Such lenses can image objects that are smaller than the wavelength of light, which would blur in an optical microscope. It can also enable laser patterning—such as is used to etch transistors into silicon chips today—to achieve smaller features.”