Foldable phones of the future could use this super thin bendable glass – CNET

Corning’s glass was shielding gadgets long before the idea of a foldable phone germinated in anyone’s imagination. The company started out in the middle of the 19th century developing heat-resistant glass for lanterns and lightbulbs, moved on to TV tubes in the 20th century and now covers many of the phone screens we use on a daily basis.  

But to fit each mold, Corning’s glass has had to evolve almost as much as the technology it covers. It’s become heat-resistant, scratch-resistant and increasingly tough to shatter. And it may soon shape the next generation of foldable displays by pushing the limits on how much glass can bend. We took a trip to Corning’s headquarters in its eponymous hometown — Corning, New York — to find out what the makers of Gorilla Glass are cooking up next and what clues it can tell us about future devices.

Finding the perfect recipe

To make glass, you need two basic ingredients: sand (silica) and a whole lot of heat. But adding different elements to the mix will result in a completely different type of glass. In fact even changing the heating temperature or the cooling time can drastically alter its properties.

This is how Corning comes up with different types of glass that can serve different purposes. Some glass, like the Gorilla Glass found on our phones, is made to be tough against falls and resistant to scratches. Glass on windshields is designed to shatter into tiny pieces (rather than sharp shards), while the glass used in laboratory beakers needs to be stable enough not to interact with the chemicals being mixed inside it.

“If you think about all the dimensions of glass, its optics, its chemical composition, its physical properties, its electromagnetic properties … we’re learning how to control all of those in incredibly precise ways,” says Jeff Evenson, senior vice president at Corning.

The first stop in our tour, and the first stage in the innovation process: Corning’s test kitchen, where these new glass recipes are tested. But instead of ovens they have rows of giant furnaces that can reach temperatures of over 1,800 degrees F, hotter than the inside of a volcano.

The mix gets put into a cauldron-like container called a crucible and placed inside of the furnace like a pizza, with long metal prongs to protect workers from the heat. Anyone in the vicinity of the furnaces wears a silver fire suit and mask, while spectators (like me and the rest of the CNET team) used dark glasses to protect our eyes. The light inside the furnace seemed as bright as the sun.

Gorilla Glass needs to cook at even higher temperatures than regular glass and when that crucible comes out of the oven, it’s glowing so bright it almost looks white. The mix inside has turned into a thick liquid that pours unto the metal table like syrup in front of us. It starts out white like the container, then fades into a neon orange as it cools, and eventually becomes clearer. The cooler it is, the less malleable it becomes and if it cools too fast it can shatter. Once it becomes transparent, it’s transferred into a special oven that can control how fast it cools. But these days Corning is testing a different type of glass recipe.

Bendable glass

With Samsung announcing its new foldable Galaxy phone and Chinese company Royole unveiling the foldable FlexPai, it’s clear that foldable phones will be a real thing in 2019. And while OLED screens have long been flexible, the product category won’t work unless those screens are covered with similarly twisty glass — which is exactly why Corning continues to push the envelope on how much glass can bend.

“To go to a tight bend radius, you have to go to a glass that’s much, much thinner than what you have today and some of the glass we have in our laboratory is thinner than a human hair,” says Polly Chu, technology director at Corning.

We got an early look at Corning’s ultrathin bendable glass, which is about 0.1mm thin and can bend almost in half like a piece of paper to a 5mm radius. It’s not its first bendable glass, but it’s a lot thinner and a lot more flexible than the Willow glass they introduced a few years back. 

I was able to hold the glass in my hands, and I had a hard time believing it was a sheet of glass and not a piece of thin plastic.

Plastic is also being considered as a potential cover material for foldable phone displays. But unlike plastic, which is prone to scratching, creasing and changing color over time, Corning says its glass will retain its integrity and color.

“If you look at what people demand on their smartphones today, scratch resistance, drop resistance, good optical properties, great tactile feel … I think glass will probably overtake plastic as the material of choice for cover material,” says John Bayne, vice president at Corning Gorilla Glass.  

But Corning’s glass is still in development, which means you won’t find it on any foldable devices yet and it may still be a slow roll to see it out in the market. The FlexpPai, which is due to start shipping in December, uses a plastic material to cover its screen while Samsung is rumored to be using a transparent polyimide alternative for its phone.

“The foldable opportunity is a little bit of a moving target now, because the use case isn’t quite and the form factor isn’t quite clear,” says Bayne. “Until these things start to manifest themselves and become more clear we’ll have to innovate in different material options in the glass space to see what the right product is … and time our development accordingly.”

Glass takes the driver’s seat

As screens continue to stretch beyond TV’s and mobile devices into other industries, manufacturers are looking at glass to cover their displays. And Corning’s glass may soon be taking the driver’s seat when it comes to automotive design. With cars become more and more autonomous, screens are popping up inside the cars for both the driver and the passenger to use as a control and entertainment center.

“Inside the car … almost all the surfaces [in the car] have shape except for this display, and so what designers are looking to do is bend those displays around the driver and around the passenger,” says Mike Kunigonis, vice president of Corning Automotive Glass Solutions.

Corning has been working on curved dashboard displays for car interiors that wrap around the cockpit and textured glass that can mimic wood and other car surfaces.

Using a technology called dead front, Corning can hide controls underneath this textured glass that only appear when the glass is backlit. This allows the controls to seamlessly blend into the console and merge into dashboard. Even the car windows have the potential to become backlit touch screens essentially turning any glass surface within the car into a usable display.

And with more glass in the driver’s seat, good visibility is crucial to keep up with safety standards, which is why Corning has also developed antireflective coatings for its glass that might be able to reduce the appearance of fingerprints and drastically improve glare. The company is also making the glass on the exterior of the car more durable. Corning has partnerships with automakers to develop windshield glass that’s more resilient to rock chips and hail.

Ford, BMW and Porsche are just some of the car manufacturers that have started to use Corning’s glass in newer cars, with over 50 more expected to roll out in the next 18 months.

The future of glass

Beyond phones and cars, Corning believes glass will continue to be play an important part in the development of new technologies that will help unlock the potential of this material.

“So far, scientists have incorporated about 50 elements from the periodic table into silica, but essentially the entire periodic table is available and I really think we’re just getting started. Think about holding the Oxford English Dictionary and the amount of words you can make with just 26 letters,” says Evenson. 

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