Scientists from McGill University in Montreal have recently developed a tougher and stronger type of glass that was inspired by the inside layer of mollusk shells. This type of glass does not shatter when impacted like typical glass but instead mimics the resilience and reaction of plastic. The applications for this new type of glass are vast, with the improvement of cell phone screens being one of the most highly anticipated consumer applications.

Existing technology

The majority of newer smartphones have Gorilla Glass screens, which is a proprietary material made by Corning and is specially engineered to take impacts, pressure and other stress that typical glass cannot withstand. Even though it is significantly more durable than standard glass, this Gorilla Glass is still easily broken or scratched due to everyday use and mishaps.

So why is creating a tough, scratch resistance glass so hard? Well, it comes down to the natural properties of regular glass. It cannot be both extremely scratch- and drop-resistant; there has to be a compromise between the two. In recent years, Corning has been focusing on drop resistance.

To strengthen glass, manufacturers typically temper it with either a heating process or chemical procedure. However, increasing the internal strength of glass makes it more susceptible to any damage on the surface. So stronger glass results in a glass that is easier to scratch, basically.

Sticking with the smartphone application, as smartphones have gotten thinner and thinner, so has the Gorilla Glass. It has had to become even stronger to deal with the reduction in thickness. Corning has achieved this increase in strength by soaking it in a chemical salt bath, while also introducing compressive stress to the interior of the glass. This stress is what helps the glass to resist drops in the future. Thinner glass equals more internal stress within the glass. This has been great for ultimate strength of the glass, but smartphone users will know that these screens scratch easily.

Glass hardening process have been around for years, with laminating and tempering of glass significantly reinforcing its strength. However, once this glass is damaged it is irreparable and it is also expensive to make. This trade off between toughness, transparency and strength has been ongoing for years.

However with new material research, scientists have created a glass that is not just five times more resistant to fracture, but also three times stronger than regular glass.

Nature as inspiration

(Learn more about glass materials on GlobalSpec.)

Using nature as their inspiration, the team developed this new glass along with a new acrylic composite that is similar to mother of pearl, or nacre. Like many new creations, the beauty of nature provided inspiration, and in this case the blueprint for innovation. Nacre, for example, has both a soft material’s durability, and a stiff material’s rigidity, which is the perfect combination. It is made up of soft proteins and chalk-like material that are stacked in layers on top of one another. This is what gives it its unbelievable strength, and it is as much as 3,000 times as strong as the individual materials of which it is composed! Nacre gives a whole new meaning to the phrase “greater than the sum of its parts.”

Mother of pearl with accrued pearls. Source: Hannes Grobe/AWI/CC BY-SA 3.0

Taking inspiration from this (and basically copying its whole composition), the scientists replicated nacre’s architecture with acrylic and glass flakes. This resulted in an easily produced material that is cheap and extremely strong but opaque. They then took the process further by making the composite transparent by modifying the refractive index of the acrylic, and blending it with actual glass to ensure that they had successfully created a totally transparent material.

Moving forward, the scientists plan to further improve the technology by integrating smart technology and giving the material the ability to modify its properties on demand. This will allow it to change its mechanics, conductivity and color. These glass features are already in existence, albeit without the improved strength and toughness of this new glass. It is commonly referred to as “smart glass” or “switchable glass”, and they are generally used to switch the transparency of the glass with the flick of a button. Voltage, heat or light is passed through a smart film that is embedded within the glass, which changes it from letting all light through to blocking some or all of the light wavelengths. Take these smart glass public toilets, located in Japan, as an example.

Is flexible glass next?

This is not referring to the new technology that has recently been seen in foldable cell phones, which is actually a variety of plastic polymers.

Actual flexible glass is thought to be a lost creation that existed around the time of Tibius Caesar, the Roman Emperor. According to some historical history sources, an inventor brought this discovery to the Emperor, by means of a drinking bowl created out of flexible glass. This bowl was tested in front of the Emperor, and when it was hit, it dented rather than shattering.

This inventor claimed that he was the sole person alive that possessed the knowledge of how to make the material. So, naturally Tiberius Caesar had him executed, as he feared that this material could become more valuable than silver and gold. Fortunately, with this glass, modern day creators will be published and rich, rather than executed!

Summary

What do you think of this new unbreakable glass? Will it save thousands of cell phone screens around the world?