The touted arrival this year of wearable gadgets such as computer displays strapped to wrists and in wrap-around glasses is just a step towards a bigger revolution in screens – those that can be bent, folded and rolled up.
Once freed from today’s relatively heavy, breakable and fixed glass displays, tomorrow’s devices may look very different, with screens that can be rolled out, attached to uneven surfaces, or even stretched. But there’s still some way to go.
“It becomes a product designer’s paradise – once the technology is sorted out,” says Jonathan Melnick, who analyses display technology for Lux Research.
There is no shortage of prototypes – South Korea’s Samsung Electronics this year showed off a display screen that extends from the side of a device – but obstacles remain: overcoming technical issues, figuring out how to mass produce parts cheaply, and coming up with devices compelling enough for gadget buyers.
Screen technology – and the global small display market is seen more than doubling to around $72 billion by 2016, according to DisplaySearch – is still dominated by liquid crystal displays (LCDs), which require a backlight and sit between two sheets of glass, making the screen a major contributor to the weight of a device, from laptops to tablets.
“Most of the weight in a tablet is the glass structure in the display and the support structure around it to prevent it from cracking,” said Kevin Morishige, a former engineer at Cisco Systems Inc, Hewlett-Packard Co and Palm.
LCD’s dominance is already under threat from lighter Organic Light Emitting Diodes (OLEDs) that don’t need backlighting, are brighter, offer a wider viewing angle and better color contrast – and can be printed onto a few layers.
From Gorilla to Willow
Glass, however, is getting lighter and more flexible.
Corning Inc, whose toughened Gorilla glass became the screen of choice for many smartphones, will provide phones with curved glass edges as soon as this year. It is also now promoting Willow Glass, which can be as thin as a sheet of paper and is flexible enough to be wrapped around a device or structure. Initially, Willow will be used as a coating for products like solar panels, but it is eventually expected to create curved products.
A key selling point for Willow is more efficient production which involves so-called roll-to-roll manufacturing, like a printing press, rather than today’s more costly batch manufacturing. But the commercialization of Willow as a flexible product is some way off, James Clappin, who heads Corning’s glass technology group, told Reuters.
And glass has its limits.
“You can bend it, but you can’t keep flexing it,” said Adrian Burden, a UK consultant who has worked on several start-ups related to display technology, and holds patents in the field. This means that while glass is likely to continue to play a leading role in devices with curved displays, screens that users can bend, fold and roll will likely be plastic.
But plastic is not as robust as glass. “As soon as you introduce plastic substrates you have all kinds of issues with sensitivity to the environment,” says Burden.
Barrier films, Nanoparticle
So while OLED and plastic would seem to be companion technologies they create an extra problem when laid together: they need so-called barrier films to prevent the various layers from leaking oxygen and moisture.
“There are barrier films in all sorts of products, for example food packaging, but the challenge is that OLED is one of the most sensitive materials we follow, and so creates huge challenges,” says Lux Research’s Melnick.
On a roll
This is gradually changing, some in the industry say, as production shifts from making parts in batches of sheets to the more efficient roll-to-roll process. “Batch is more expensive and slower than roll-to-roll, which needs new equipment and design – and takes time,” said Ramadas at Tera-Barrier.
All this requires money, and manufacturers have to be convinced to invest in the new equipment.
Even after the success of Gorilla Glass, popularized by the Apple Inc iPhone, Corning is having to work hard to prepare customers for Willow displays. Clappin said customers want thinner devices and easier to produce glass, but Willow requires a completely different manufacturing set-up.
“When we talk about commercializing Willow a big part of our development activity is enabling the ecosystem to handle what is essentially a brand new material,” Clappin added. “Nobody’s accustomed to working with glass that bends and moves. It’s a new material. The ecosystem needs to be trained to handle it.”