Exclusive: Here's the bendable glass that could come to your foldable phone

The makers of Gorilla Glass are working on an ultrathin bendable glass that could help protect the next wave of foldable phones.

Vanessa Hand Orellana CNET Senior Editor
As head of wearables at CNET, Vanessa reviews and writes about the latest smartwatches and fitness trackers. She joined the team seven years ago as an on-camera reporter for CNET's Spanish-language site and then moved on to the English side to host and produce some of CNET's videos and YouTube series. When she's not testing out smartwatches or dropping phones, you can catch her on a hike or trail run with her family.
Vanessa Hand Orellana
5 min read
Sarah Tew / CNET

When it comes to foldable devices like the the Royole FlexPai and Samsung's unnamed foldable phone, this major question inevitably comes up: Is that screen made plastic or glass? Plastic looks cheap, but today's glass screen are more likely to break than flex when you bend them. Maybe not for long. CNET got an exclusive look at an ultra thin bendable glass that Corning -- the company behind the Gorilla Glass screen topping most of the world's phones -- is developing at its headquarters in upstate New York.

As the foldable phone trend picks up steam in 2019, there's potential for every company that makes mobile phone parts, from the display to the battery to the cover material that tops it all, to become involved in the new phone design. The foldable phone design may not be as dedicated a revolution as the shift from 4G to 5G technology, but it could help revive an industry that's become static from slowing sales and same-old rectangular construction.

A phone that can fold, and a glass screen along with it, doesn't just add sizzle. It also extends what you can do on a mobile phone. Instead of one big screen, you have two to use in various configurations. Open it up completely and you get a screen the size of the tablet in a fold-up shape the size of your usual phone.


A foldable phone like the Royole FlexPai needs a foldable screen.

Angela Lang/CNET

If Corning can beat out competitors to supply bendable glass for foldable phones, it can literally help shape the next wave of phones.

Bendable glass for foldable phones

Samsung, Huawei and LG all announced their intention to make foldable phones in 2019. And while OLED screens have long been flexible, this type of device 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.


Corning's ultrathin bendable glass is still in development, but it can fold almost in half. 


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

Corning's ultrathin bendable glass 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 Corning exclusively showed CNET a few years back. We were able to hold the glass in our hands, and had a hard time believing it was a sheet of glass and not a thin piece of 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 color and structure.

"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," said John Bayne, vice president at Corning Gorilla Glass. 

Corning's glass is still in development, which means you won't find it on any foldable devices yet and it may roll out slowly. The Royole FlexPai, which is due to start shipping in December, uses a plastic material to cover its screen while Samsung is rumored to be using a similarly transparent polyimide alternative for at least part of its phone.

Watch this: The bendable glass that’s shaping up to cover foldable phones

Samsung hinted at its developer conference in November that its foldable phone might have one glass topper for the static screen and perhaps a plastic cover material for its bendable screen, but the company hasn't confirmed the design.

"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," said 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."

Samsung's foldable phone is here, with brand-new One UI for Android

See all photos

Glass takes the driver's seat

As screens continue to stretch beyond TVs 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 becoming more and more autonomous, screens are popping up inside the cars for both the driver and the passenger to use as control and entertainment centers.

"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," said Mike Kunigonis, vice president of Corning Automotive Glass Solutions.


The curved glass in the interior of the car transforms the entire surface into a usable display. 

Sarah Tew/CNET

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.


This textured glass looks and feels like wood and can hide the icons when the light is turned off. 

Sarah Tew/CNET

Using a technology called dead front, Corning can hide controls underneath this textured glass that only appear when the glass is backlit while they're in use. This allows the controls to seamlessly blend into the console and merge seamlessly 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 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.

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," said Jeff Evenson, a Corning senior vice president.

"So far, scientists have incorporated about 50 elements from the periodic table into silica, but essentially the entire periodic table is available," he said. "I really think we're just getting started."


Glowing glass pouring down like syrup onto the metal sheet. 

Sarah Tew/CNET

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