TechTheDay

In an earlier post, we discussed the possibility of sapphire glass becoming the standard for device display protection. Sapphire glass indeed has its advantages but what if there is another solution that is cheaper and more convenient to use? What if the already tough Gorilla Glass or DragonTrail glass on your device can be made shatter-proof without waiting for Corning or Asahi to do the improvements?

Looks like this is now possible with a new technology developed at the University of Akron in Ohio. It is a coating that can be used on glass and polymer surfaces. It matches and can even outperform currently available similar solutions. It is better than putting a plastic shatter-proof display sheet similar to what Sony did to Xperia Z and Z1. It may even be better than having the expensive sapphire glass covering the display of a device.

Copper Nanowire Coating

Researchers at University of Akron have created a coating for glass that adds better flexibility and toughness using copper nanowires. Yes, it’s nanotechnology at work again. The work was made public in a recently published paper that provides details on how to apply a thin and transparent layer of electrodes on a surface used for touch displays. The research team was led by Yu Zhu, an assistant professor of polymer science.

The nanowires here mainly refer to the microscopic copper wires that are linked together to form a network that covers the entire screen. These copper nanowires are then overlaid with a polymer called polyacrylonitrile (PAN), electrospun with the nanowires. Everything is then made flat and homogenous through the process called solvent annealing, which involves both heating and cooling. The coated glass (or polymer sheet) is then soaked in a metal etching solution to get rid of the copper nanowires that have not been masked by the PAN fibers. After this, the PAN fibers are also removed using an organic solvent that the copper nanowires are able to resist. The final product is a glass or polymer panel with just the clear film of copper nanowires on top of it, providing durable protection and conductivity on the glass or polymer panel.

Advantages of the Copper Nanowire Coating

• As mentioned, the nanowire coating provides added durability to the glass. It can make the coated panel shatter-proof. It does not make the glass unbreakable but it makes the glass slightly tougher and prevents the glass displays of mobile phones or tablets from shattering into small dangerous pieces that can easily puncture the skin or enter the body and cause unpredictable serious damage.

• Another advantage of the nanowire coating developed by University of Akron researchers is its higher level of conductivity. Compared to indium tin oxide, copper is more conductive. Plus, it does not wear off from the glass or polymer to which it is attached. The researchers tested the conductivity retention of the coating they created by doing a 1000x cycle of repeatedly sticking and removing Scotch tape on the panel. No conductivity loss was observed after doing the process.

• Copper nanowires also offer the benefit of being usable on polymer sheets. It is not only intended for glass. It can also be used on plastic display covers. This means that, in the future, rugged, flexible, and shatter-proof display panels made of polymer will already be possible.

• Graphene based electrode coatings have already been developed in the past and they are considered as viable alternatives to ITO. However, they are relatively expensive to produce. University of Akron’s copper nanowire coating is deemed as a cheaper option. Moreover, nanowires offer the advantage of being produced right on the glass instead of being prepared separately before getting meticulously transferred to the glass panel.

Important Points to Emphasize

It has to be emphasized that the newly developed nanowire coating mentioned here only makes the glass shatter-proof. This means that it does not make the glass resistant to breakage although it can possibly slightly increase the durability of glass to some extent. A nanowire-coated glass can still break when dropped or subjected to high levels of pressure and tension. Shatter-proofing only guarantees that the glass shards will not scatter dangerous when the glass breaks, especially when the device is dropped.

Additionally, the nanowire coating can make the display usable even when the protective glass is already broken. It can help prevent or minimize the protrusion of glass shards on the display, making the broken display safe to use if the display can still turn on. This nanowire coating, however, is not a substitute for the durability and scratch-resistance of tempered glass such as Gorilla Glass and DragonTrail.

Hopefully, this new tech will be available soon and used by major device manufacturers such as Apple and Samsung. It is a very useful technology with palpable benefits. It is a better feature for device manufacturers to pursue instead of proceeding with the senseless display resolution competition.