Glass manufacturer Corning is working on a foldable glass that can bend tightly and is thick enough to be durable. That's proving to be something of a roadblock right now, as the company's general manager John Bayne says working on something like that is like challenging the laws of physics as to achieve a very tight bend radius, the thickness of the glass has to be reduced and the thinner you go, the less resilient the glass becomes. A thin glass would be more prone to breakage in the event of a drop and thus, it wouldn't be suitable for smartphones.
The Gorilla Glass manufacturer is currently working on a glass that's just 0.1 millimeters thick and bends to a 5mm radius. The technical challenge faced by the company is to stay within the 3mm to 5mm bend radii range whilst ensuring the glass is damage resistant. The company is trying to combine its rollable Willow Glass and Gorilla Glass but the manufacturing process has rendered the former useless. Willow Glass must be dipped in a molten glass solution and this can corrode the transistors of the display.
Although Corning has readied some working solutions and sampled them to clients, they do not satisfy all the requirements. There is a tradeoff between resilience and tight bend radius and the company just isn't willing to compromise on either of them. It wants to make a glass that's ultra thin, durable, and bendable. Corning is hard at work to come out with an optimal solution and it will hopefully be ready in a couple of years. Other manufacturers, such as Japan's AGC, are also working on similar solutions and in a few years, glass might replace plastic that's being used on the first generation of foldable smartphones.
The Samsung Galaxy Fold and Huawei Mate X have already been unveiled, but both the companies are noticeably queasy about letting journalists handle the devices before they are officially released. This has raised all kinds of speculations about the software, dimension, and most importantly, the display quality of the two phones. Apparently, both the devices have a crease towards the middle of the display, which is kind of an eyesore. While the crease might not be that visible initially, it is only going to get worse over time.
The first generation of foldable smartphones are all going to use plastic polymers. Unlike glass, which is strong and durable, plastic isn't that resilient. However, since glass cannot fold like a book right now, manufacturers had no choice but stick with plastic. So while plastic seems like a suitable candidate for making bendy devices, it is prone to scratching which means that the quality of the display would degrade really quickly. Explaining things further, John Mauro, who previously worked at Corning and now teaches material science, said that the molecules within polymer rearrange themselves after a stress event, while glass will recover after deformation.
The difference will be all the more visible to consumers as a plastic display has nothing on an OLED screen which most high-end smartphones come with these days. However, until glass manufacturers come out with a solution, smartphone makers will have to make do with polymers. Whether customers will be fine with that remains to be seen. However, the initial foldable smartphones are going to be more of niche devices, and manufacturers are likely to bank on their exclusivity to drive up sales. So, maybe a slight crease in the middle of the phone isn't going to be much of a problem this year.