Over the past few years, the top smartphones have converged onto the same form factor: a large touchscreen display on a rigid slab-like device. With flexible displays just around the corner, is it time for a revolution in smartphone design? Will we see the re-birth of the flip phone?
Over the last couple of years, we’ve seen a fierce battle amongst mobile manufacturers to produce bigger smartphones with faster processors and sharper displays. Much of this has been in response to the launch of the iPhone 6 years ago. Since then, mobile phones have converged on the same form factor and the old selection of flip phones, slider phones and swivel phones has disappeared.
With flexible displays just around the corner, there’s suddenly an opportunity for mobile phone manufacturers to create new and innovative form factors. Flip phones might be on the way back in and we could see new devices that bridge the gap between a watch, smartphone and tablet.
In this article, we chart the history of flexible displays and ask whether flexible displays could lead to a revolution in smartphone design.
Today’s smartphones have largely converged on the same form factor: a form factor that has barely changed since the original iPhone in 2007. From left to right: Apple iPhone (original), Samsung Galaxy S III, Google Nexus 4, Sony Xperia Z, HTC One and Nokia Lumia 920.
Flexible displays have been in development for almost 40 years now. Fed up with the amount of paper that is wasted and thrown away in offices, engineers at Xerox PARC created the first electronic paper displays in 1974. Designed to replace physical paper, their Gyricon e-paper displays could be bent and distorted just like normal paper. This original image would stay on the display: regardless of whether it was kept flat.
Today, the bestselling Amazon Kindle e-book reader uses a variation of electronic paper technology. The Kindle’s body houses an electronic paper display as well as hundreds of other components (a battery, processor, wi-fi radio, etc). Although the display itself is in principle flexible, Amazon has decided to keep the device rigid as other components housed within it are not flexible.
See also: Our guide to how e-ink displays compare with LCD displays.
Although electronic paper displays have been flexible for almost 40 years, smartphones and tablets typically use displays based a different type of technology: LCD and Organic LED (OLED) technology. Compared to electronic paper, LCD and OLED displays offer faster response times and better colour reproduction. They also give sharper and higher-resolution images. This has made them popular as they allow multimedia consumption and super-high resolutions as found on today’s 1080p smartphones.
Over the past decade, mobile phone companies have worked on making their displays flexible. This work has primarily focussed on the organic LED (OLED) technology. This is because LCD technology doesn’t lend itself to being flexible: the individual pixels on the display cannot emit light so there needs to be a rigid backlight behind the display. With OLED technology, this problem doesn’t exist as each pixel can emit light directly. There is no need for a rigid backlight and the display continues to provide sharp and accurate images even when flexed.
This year, Samsung has started to produce mass-producing flexible displays under the “YOUM” brand name. During last month’s CES, they demonstrated several devices with a flexible OLED display. With the technology now available to mobile phone manufacturers, it’s only a matter of time until we see it in mainstream consumer devices.
The advent of YOUM and comparable technologies from other manufacturers means that there are now flexible, high-resolution displays suitable for use in a mobile phone or tablet. These displays continue to give the vibrant colours and sharp images that are expected by consumers but they also give manufacturers to potential to bend and twist the displays to create new and novel form factors.
Nokia (left) and Samsung (right) have been showing off their ideas about what the mobile phone of the future might look like.
Nokia kicked things off in 2008 by imagining what a future flexible smartphone might look like. Their Nokia Morph concept device is able to “morph” between different form factors: it’s primarily a phone but it can be expanded to give a larger tablet-like form factor and it can be folded up to give a wristwatch that attaches around your arm. With the ability to morph between shapes and sizes, you can have a single device for your entire life – something that’s big and gives a great experience when you want to view multimedia and something that’s small and portable for when you’re out and about. The display can also flex outwards whilst you’re typing to give real 3D buttons and tactile feedback. You can watch the Nokia Morph concept video here.
More recently, Samsung has produced various concept videos to promote their YOUM displays. This concept video shows a transparent flexible screen that can act as a camera, newspaper reader, language interpreter and phone. They also showed a concept video at CES where one of their smartphones could fold open and transform into a tablet.
Whilst the concepts from Nokia and Samsung are impressive, they’re still a long way off. Whilst the technology already exists to make flexible displays, other components that are found within a smartphone are still rigid. Until we additionally have flexible batteries and flexible components, it’ll never be possible to build a fully-flexible smartphone.
To this extent, today’s working prototypes feature more basic uses of flexible display technology.
In 2011, Nokia demonstrated a prototype of the Nokia Kinetic “bendy” phone. Whilst the phone isn’t fully-flexible, it can be twisted and bent to some extent. In the prototype, menus could be scrolled by twisting the phone and phone calls could be answered by squeezing the phone. According to Nokia, it can be a new and tactile way of interacting with your phone – a complement to today’s touchscreen navigation technologies. You can see a video of it in action here.
More recently, Samsung has shown off a prototype smartphone with a curved display. Making use of their flexible display technology, the screen is made to curve around the edge of the device. The curved part of the screen shows additional information such as text messages and stock prices. The result is that you can see notifications without picking your phone off the table. Whilst the device itself isn’t flexible, it makes use of flexible display technology to create a new form factor.
Two prototype devices that utilise flexible display technology. These are the Nokia Kinetic (left) and a Samsung YOUM prototype (right).
Another form factor that could benefit from flexible displays is the flip phone, or the folding tablet. Sony experimented with a folding tablet in 2011: the Sony Tablet P featured two 5.5-inch displays. When opened, the two displays on the tablet could be used together for surfing the web and watching videos. Unfortunately, there was a large gap between the two displays making the experience somewhat unconvincing.
Using their flexible display technology, Samsung has recently demonstrated a single display that can be folded down the middle. This technology could be used in a flip phone or a folding tablet: the screen would be able to span both sides of the device without there being a gap in the middle. This allows video and webpages to span the entire device when needed. Furthermore, this form factor does not require a flexible battery or flexible processor as the components can be housed within the rigid halves of the device. It has been rumoured that Samsung will release this device in the future as the Galaxy Q.
The Sony Tablet P (left) was a foldable tablet that used two separate displays. Using flexible display technology, the tablet could use single foldable display (right) with there being no gap across the middle of the device. This design could also be useful in a next-generation flip phone.
Looking into the future, the technologies for a fully-flexible smartphones aren’t likely to be ready for another decade.
Last month, scientists demonstrated the first flexible battery. The battery could be twisted, folded and stretched to 3 times its original size and would continue providing power as normal. Although the primary interest is in developing medical applications (i.e. devices that can be implanted within the body), the development of flexible batteries is significant for fully-flexible smartphones. This technology will need to be refined and taken to manufacture.
To make the rest of the phone flexible, components such as the processor will also need to be flexible. In scientific circles, there’s currently a large amount of interest in graphene. Graphene has been described as a “miracle” material: it’s flexible, transparent, ultra-thin and conductive. With further research, it should be possible to build electronic devices from graphene. These devices would have the potential to be fully-flexible.
With further research in the fields of flexible batteries and graphene electronics, fully-flexible smartphones could become a reality in the next decade.
In this article, we’ve taken a look at flexible display technology. Since its birth almost 40 years ago, flexible display technology has now evolved to the point where it can be used in next-generation smartphones and tablets. This opens the way for a new generation of form factors: bendable smartphones and foldable tablets for instance.
Are you excited about flexible display technology? What innovations and new designs would you like to see from mobile phone companies in this area? How long do you think it’ll be until we see flexible devices on the market? We’d love to hear your thoughts… please drop us a comment below and let us know what you think!
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