Bending toward a foldable future

Despite defying all normal expectations of what glass is like, Corning’s ultra-thin bendable glass—capable of flexing, flipping, folding, and even rolling—is the real thing. And, with Corning leading the way, it’s the type of glass that can radically transform displays—on phones, TVs, laptops and in cars—for years to come.

“The first time I got my hands on samples of it, I kept thinking over and over, I can’t believe this is glass,” said TJ Kiczenski, Research Fellow, Glass Research, who led Corning’s bendable glass research team for two years.

Bendable glass is simple in concept. It’s glass, formed ultra-thin, that can bend repeatedly without breaking. But in practice, Corning scientists solved a complex set of technical challenges to make the glass viable for real-world applications.

Opposing forces

Take, for example, a cell phone with a display that folds in the middle, either horizontally or vertically.

“The attributes that everyone wants – a durable device that folds easily – are on opposite ends of the spectrum,” said Ellyn King, Research Technology Manager, Bendable Glass Technologies. “How do we make the glass thin enough to bend easily, while keeping it strong enough to be reliable? Our job is to figure out how to balance those properties.”

Corning has developed a variable thickness glass innovation--Corning® VtG™--which features thinner glass at the point of the hinge and thicker glass on the rest of the cover glass sections, known as the wings. This design allows for a device with both effortless bendability at the hinge area and added display durability when compared with a monolithic thickness piece of glass due to the thicker glass on the wings.

Additionally, as the bend radius gets smaller, the amount of stress that’s placed on the glass increases.

Enter Corning’s proprietary ion-exchange process, which introduces a layer of compression to the glass’ surface.

“Ion-exchange is an incredibly important part of making ultra-thin glass viable for a bendable glass application,” said Ellyn. “In order to counter the stress caused by the bend, we introduce a significant amount of compression on the surface of the glass, so that it can survive the tight bend radii of foldable devices.”

As the device folds--and the glass bends--the glass is placed in simultaneous states of compression on the inside and tension on the backside. Managing potential flaws that can withstand both tension and compression is incredibly difficult. And while chemical strengthening via ion-exchange plays a significant role in addressing those flaws, Corning has also developed advanced, end-to-end manufacturing capabilities to minimize the probability that flaws will occur in the first place.

A fully integrated, end-to-end supply chain

Before becoming device-ready, Corning’s ultra-thin glass undergoes a complex multi-step finishing process. In addition to ion-exchange, the finishing process involves cutting, washing, and etching the glass – all while maintaining a virtually flawless surface.

“Bendable glass only functions properly if the surface of the glass is as pristine as possible,” said Peter Lezzi, Senior Development Associate, Bendable Glass, who has spent the last decade working on the program. “Even the best glass won’t perform to its full potential without proper finishing techniques. What Corning brings to the table is wide-ranging expertise not only in glass composition and manufacturing, but also in finishing processes and the ability to provide technical support to our customers.”

To leverage the full extent of that expertise, Corning established the world’s first fully integrated supply chain for ultra-thin bendable glass in 2023. Corning’s fully integrated supply chain helps ensure advanced quality control throughout the entire manufacturing process, including the complex finishing steps needed to produce advanced bendable glass products.

Folding into the future

Are foldable devices a novelty or here to stay? Corning experts are betting on the latter.

“It’s the logical progression. How do you get a bigger display onto a device that fits into your pocket? You’ve got to be able to fold it up. Our pockets aren’t getting any bigger,” said Peter.

Ellyn agreed with the potential staying power, saying, “Bendable glass can help enable serious technology changes in both the mobile consumer electronics and automotive sectors.”

In addition to foldable phones, Corning’s bendable glass has the potential to help unlock a wide array of next generation device designs, from laptops and tablets to handheld gaming devices. Or, bendable glass can fold away into an automotive interior, maintaining a sleek design and saving essential space in a car.

“There are infinite possibilities,” said Archit Lal, Business Director for Corning bendable glass. “Imagine sitting in the driver’s seat of a car and initially there’s nothing. Suddenly, a large screen rolls out right in front of you.”

And then when you get home, there could be more bendable glass technology making life easier.

“Say you’re in an apartment in Manhattan or Seoul where space is limited. Your TV now just sits in a room and takes up space,” Archit continued. “In the future, you could just roll it back into the wall. That’s the power of bendable glass.”

Whatever the future holds for foldable, rollable, and bendable devices, Corning has positioned itself squarely at the forefront of bendable glass innovation.

“We’re constantly being challenged to do the impossible,” said Ellyn. “But when we really get into it, we find ways to drive things forward. If it can be done, we’ll make it happen.”