Apple supplier Corning working on foldable glass for future phones

Corning is developing glass that can be repeatedly folded, and reports that it is on track to manufacture it in quantity in a couple of years when foldable phones are in the mainstream. While Apple has not commented on its plans for foldable phones, the company has used Corning since the very first iPhone.

"We have glasses we've sampled to customers, and they're functional, but they're not quite meeting all the requirements," says John Bayne, senior vice president and general manager, Corning in Wired. "People either want better performance against a drop event or a tighter bend radius. We can give them one or the other; the key is to give them both."

The company is currently using glass that is 0.1mm thick and can be bent to a 5mm radius.

"The back of the problem we're trying to break, the technical challenge is, can you keep those tight 3- to 5-millimeter bend radii and also increase the damage resistance of the glass," says Bayne. "That's the trajectory we're on."

Wired also spoke to Professor John Mauro, now at Penn State University, and previously an employee of Corning. He said that current foldable phones use plastic polymer because glass isn't ready yet.

"The polymer is better at flexibility, it's easier to bend at the same thickness," Mauro said. "The molecules can rearrange themselves more easily in response to stress, whereas the glass has a more rigid structure."

Mauro says Corning may be being conservative in its estimate of how long it will take to produce suitable glass.

Apple did attempt to move away from Corning Glass in 2014 when it pursued sapphire glass with GT Technologies. However, that deal failed and left GT Technologies bankrupt.

Currently Apple does use sapphire glass in certain Apple Watch screens plus Touch ID fingerprint sensors, and the protective cover on the iPhone's rear-facing cameras.

Current foldables from Samsung and Huawei use plastic polymers that bend well, but are not as hardwearing as glass.