The Secret Sauce Behind Flexible Displays
The display world is going flexible. Apart from withstanding the pressure when people sit on them, legacy smartphone displays aren’t designed to be flexible. But now that Samsung and other players are or soon will be introducing flexible and foldable smartphones, tablets and wearables, the industry is coming up with new materials that produce flexible touchscreen displays.
The challenge with touchscreen displays is that they must conduct electricity in order to present icons, text, graphics or video, and they must also be as clear as possible. Until now, display manufacturers used Indium Tin Oxide (ITO) as the basic material. ITO is conductive and relatively transparent, all right, but it’s also rigid so it cracks or breaks when the display is flexed. Silver nanowire-based materials are promising because they are flexible and foldable and are easier and less expensive to use.
Silver nanowire-based materials have four key advantages over ITO:
- Superior optical and electrical properties – Silver nanowire-based materials deliver the highest conductivity with the best optical quality in the market. Silver nanowire-based materials deposit an open and relatively transparent conductive grid on the display substrate. Because the grid is open and made of nanomaterial, it is more transparent, less hazy and offers sharper resolution.
- Flexibility – Silver nanowires are very small and highly flexible. They can withstand 100,000 or more bend cycles.
- Manufacturability – Silver nanowire material is easier to manufacture than ITO. Unlike ITO, which requires sputtering in a vacuum chamber for ink deposition, silver nanowire can be deposited as a solution using standard solution processing equipment. Electronics manufacturers can make more silver nanowire-based displays more quickly than ITO-based displays.
- Low cost – It is far less expensive to manufacture display coatings with silver nanowire than with ITO, largely because silver nanowire can be applied to a display substrate using standard solution processing methods. Slot die coating is one of the solution processing coating methods, and most electronics makers already have slot die coating machines, so they don’t need to add new equipment. (Silver nanowire also supports other coating processes.) Overall, using silver nanowires can be ten times less expensive than using ITO due to the savings in capital equipment costs, streamlined processes, and faster processing.
So far, there are only two companies making silver nanowire-based materials for conductive displays, C3Nano, the performance leader in silver nanowire-based transparent conductive inks and films, and Cambrios. As the industry moves toward flexible interactive displays, we will likely see larger companies like 3M and Nissha enter the market.