How are foldable smartphones moving in the future? We learned that smartphones and tablets would have flexible screens back in 2013 when Samsung introduced its ‘Youm’ display on CES, but we just found them in a device that wasn’t an idea until last year.
However, within a short period, foldable television technology seems to have sufficiently evolved that LG made a rolling TV last year. It came into the limelight at its CES 2019 booth. While all that is fantastic, the folding OLED displays are sensitive, suggesting that they do require a security layer in the real objects, like in a smartphone. So they need glass that can be folded.
Till now, all the bendable cell phones have used plastic shielding covers as simple scratch resistance on the OLED screen. Yet these aren’t enough to last long or even for short-time endurance. Consider taking last year’s Samsung Galaxy Fold, which revoltingly failed in a resilience test. The Motorola Razr (2019) has also recorded some defects, varying between the display crashing apart within a week of usage and the collusion of the axis within just 4 hours of spinning for opening or closing it.
This year’s Samsung Galaxy Z Flip became the first handset to include a foldable glass screen. When we saw it for the first time at the launch case, it sure seemed like the real thing, with no actual signs that the display is unstable or sensitive. Even so, it pointed out that it is similar to the ordinary scratch-resistant glass today in longevity and fared almost as bad as the Galaxy Fold and the Motorola Razr (2019) during an endurance test.
Similar to the one used in the Galaxy Z Flip, foldable screen or ultra-thin glass (UTG) is still a first-generation feature, meaning it still has a long way to go before such glass can be as stable as those used on standard phones today while still being rigid. Mathias Mydlak, a Global Business Development Manager at Schott stated that the thickness is the major distinction between the flexible and conventional flat glass in addition to certain different “magic ingredients”.
Bendable glass is essentially glass that’s been stretched thin enough and then treated so that it can bend back and forth, without permanently losing its shape. However, according to Mydlak, the biggest issue is to make glass thin to the point where it is flexible. He also added that they defined Ultra-thin glass (UTG) by achieving a thickness of below 0.1 mm.
Schott claims it’s been using UTG glass for other applications for the past couple of decades and has a specially developed ‘down draw process.’ Here, a ribbon of glass is pulled back from the top, moving through different drums and via a cooling track to achieve the final outcome.
Schott is one of the few glass manufacturers on the market which already has a versatile glass solution. Samsung, one of its customers means that Schott most probably provided the UTG glass in the Galaxy Z Flip. Corning is also thought to work with phone manufacturers to incorporate their alternatives. A spokesperson for Corning ensured that they are working on that task with their clients and are currently evaluating their production glass with them to customize the product to suit their design requirements.
So far, that doesn’t appear to be the case. If we take the Galaxy Z Flip as an example, the durability test of a popular YouTube channel revealed that the UTG glass scratched just as easily as the plastic screens at the Galaxy Fold and Motorola Razr (2019). Indeed, a vigorous indent made by a fingernail also seemed to leave a permanent scratch on the glass.
Schott maintains that the scratch resistance of bendable glass is in the same range of regular, thicker glass and that all of this depends on the toughening process. “Separate glass-processing companies do the toughening processes. Therefore it depends finally on their processing steps and recipes, “Mydlak said. While Schott or Corning could provide the raw materials, this means that the hardness or longevity still relies on what kind of treatment the smartphone maker gives it, as well for now.
While Corning believes that a lot of work remains to be done before foldable phones are as durable as normal ones. “Generally, we believe today’s material sets of plastic options and options for glass do not meet all the desired attributes of a bendable device,” a Corning official told. Corning however states that in its R&D, foldable technology has already shown success in the thickness range of 30-100 micrometers.
The greatest durability challenge for foldable glass is its ability to maintain its structural integrity even after years of folding and unfolding, in addition to being able to resist scratches. Corning believes that while maintaining its flatness its developmental glass-based solution can bend more than 200,000 times without damages. Meanwhile, Mydlak stated that the lifetime of the foldable glass ultimately depends on the device manufacturer’s final design and processing. Another issue commonly found in foldable devices is a noticeable folding crease, which is normal but also draws attention away from the feeling of having a fairly flat screen.
The production cost of foldable glass is also higher compared to the traditional one of the same size. Although Mydlak did not comment clearly on how much more expensive it would be, he said that in the future both could be on a similar level at some points, provided that enough people are buying devices with bendable glass.
It is not expected that foldable technology anytime soon to be widely popular but that doesn’t mean it won’t. There was a time when even flagship phones came with a single camera. Today, most of us won’t even look at the budget phone if it doesn’t have at least three cameras and that’s just on the back. When technology advances, it can revolutionize the way we use smartphones. So this new feature can also bring a revolutionary change in the trend of smartphone technology.