What's a graphene display and why it's going to be in flexible smart devices from the future
Yesterday, a Chinese manufacturer whose name escapes us turned a few heads by showing a working and completely flexible Android smartphone which uses a graphene screen. The invention is shaped like a bracelet and has no problems wrapping itself around a lady's hand, for example. This glimpse of the feature reminded us that leading smartphone makers already have flexible displays in mass production, but they still choose to incorporate them in devices that are absolutely flat and un-bendable. It also sparked our interest in the never seen in use before piece of technology that is the graphene display.
What's graphene?
Graphene research has been particularly fruitful in the fields of electronics and biotechnology, although there's still work left to do before the element can be produced in a safe and cost-efficient manner. With development in this direction steadily progressing since 2012, when an important scientific discovery proposed a less toxic method for obtaining high-quality graphene, it's no surprise that display manufacturers, along with other technological enterprises, are heavily interested in the material.
Yesterday marks the first time we've seen graphene used in a flexible smartphone display, in a manner that makes not just the screen, but the entire device fully bendable. Clearly, the future of flexible smart devices that can be worn or experimented with by clever designers will involve the application of graphene, in addition to the already familiar plastic OLED technology used by Samsung, LG, and Apple for their smartphones and smartwatches. So here's an informative look at what a graphene display is right now, along with its questionable near future.
The first flexible graphene display (pictured) was prototyped in September 2014 by two partnering institutions – the University of Cambridge Graphene Center and UK firm Plastic Logic. It was a monochrome screen, similar to that of e-readers. The invention might seem limited, but it's an essential step towards the wearable and flexible smart devices the future has in store.
This particular display, and possibly others that followed it – like the one on the Chinese smartphone we saw yesterday – works on the principle of active matrix electrophoretic. It uses an electric field to output images via re-arranging particles suspended in a solution. The layer of emulsion-processed graphene electrode is deposited onto a flexible plastic panel and etched with electric circuits. There's no intrinsic requirement for using glass sheets, which means graphene displays won't be subjected to the kind of impact damage sustained by glass-covered screens.
Moreover, this sort of display should be easier to produce than flexible OLED screens, because its backplane – the electrical layer which supplies power for re-arranging display particles – can be produced using a low-temperature process (at below 100° C / 212° F), which minimizes yield risk and makes the production less resource-intensive.However, smartphone graphene displays will likely use elements from LCD and OLED technology to provide the kind of colors and refresh rates needed for an adequate user experience. This will inevitably complicate production somewhat.
About five months later, researchers from the University of Manchester and University of Sheffield introduced a semi-transparent, graphene-based LED screen, which is the basis for the flexible graphene displays that will end up in future mobile devices. Being only 10 to 40 atoms thick, it emits light across its entire surface without the need for a backlight.
What's a graphene display?
This particular display, and possibly others that followed it – like the one on the Chinese smartphone we saw yesterday – works on the principle of active matrix electrophoretic. It uses an electric field to output images via re-arranging particles suspended in a solution. The layer of emulsion-processed graphene electrode is deposited onto a flexible plastic panel and etched with electric circuits. There's no intrinsic requirement for using glass sheets, which means graphene displays won't be subjected to the kind of impact damage sustained by glass-covered screens.
Moreover, this sort of display should be easier to produce than flexible OLED screens, because its backplane – the electrical layer which supplies power for re-arranging display particles – can be produced using a low-temperature process (at below 100° C / 212° F), which minimizes yield risk and makes the production less resource-intensive.However, smartphone graphene displays will likely use elements from LCD and OLED technology to provide the kind of colors and refresh rates needed for an adequate user experience. This will inevitably complicate production somewhat.
About five months later, researchers from the University of Manchester and University of Sheffield introduced a semi-transparent, graphene-based LED screen, which is the basis for the flexible graphene displays that will end up in future mobile devices. Being only 10 to 40 atoms thick, it emits light across its entire surface without the need for a backlight.
When are graphene screens coming to smartphones?
We don't know! For the time being, graphene is too expensive to be used in large-scale production of touch-screen displays. And besides, there's much work to be done before a graphene screen can compete with a fine LCD or OLED screen in terms of image quality. Hence, its introduction to smartphone displays is more likely to start on the level of touch screen controllers.In late 2014, researchers from the University of Surrey and Trinity College, Dublin developed a "simple, scalable, and inexpensive method for creating hybrid electrodes by combining graphene (with its transparent and conductive properties) and silver nanowires. Their accomplishent is in reducing the amount of nanowires needed to produce a touch screen layer more than 50 times, thus simplifying the production process. This concoction could replace the indium tin oxide layer technology that's currently in use, although we're yet to see it appear in consumer devices.
