Samsung Channels Gumby With Unbreakable, Bendy Phone Screen
Nov 15, 2012 2:05 PM PT
Samsung is gearing up to produce plastic flexible displays for mobile devices, the Wall Street Journal reported. The screens are lightweight, nearly unbreakable, and could result in flexible devices down the road.
The displays, made from flexible organic light-emitting diodes, reportedly will be released in the first half of 2013.
Samsung's move is seen as a bid to remain ahead of the field, as competitors such as Sharp and LG Display introduce different screen technologies for mobile devices.
"Flexible AMOLEDs can help Samsung differentiate its products in a smartphone market where most products offer similar products and functionality," said Vinita Jakhanwal, director of mobile and emerging displays and technology at IHS Electronics and Media.
The Competitive Advantage
Mobile device display technology has been progressing by leaps and bounds, and, until recently, Apple's Retina display was the top of the heap in terms of resolution. It offers 1136 x 640 pixels on the iPhone 5 and 5th-generation iPod touch's screens, and 2048 x 1536 pixels on the 3rd and 4th generation iPads' screens.
HTC's Droid DNA smartphone now tops that with 1920 x 1080 pixel resolution on its 5-inch screen.
"The display is the most critical part of any consumer electronic device," said Jim McGregor, founder and principal analyst at Tirias Research. "Not only do its sharpness and brightness help determine the overall user experience, but it can have a huge impact on weight, thickness and power consumption. Being able to use plastic AMOLED displays would be a huge competitive advantage."
Flexible Display Technology
Flexible OLEDs incorporate a flexible plastic substrate on which the OLED is deposited. Regular OLEDs are usually made on a glass substrate, but the substitution of flexible plastics such as polyethylene terephthalate enables the manufacture of screens that are both flexible and lightweight.
It's been suggested that one production method might use a technique derived from inkjet printing.
This "is similar to the process adopted by flexible solar arrays, but there are always challenges and tradeoffs in developing a new technology, especially when it comes to manufacturing," McGregor told TechNewsWorld.
Pros and Cons
Depositing layers onto a flexible substrate might cause residual stress. There might also be thermal stresses because the different materials used expand and contract at different rates on heating and cooling. Bending a flexible display further stresses the material.
Further, Indium tin oxide -- the material most commonly used as the transparent anode -- is brittle, and, if it fractures when the display is folded or bent, its sheet resistance might increase, or it might disrupt the layered structure of the OLED.
All these sources of stress may lower the efficiency or brightness of the display or cause it to break down completely.
"You don't necessarily have to let the user flex the screen," McGregor pointed out. "You can just use the flexible display as a regular display with a larger surface area. In this case, the display would probably last longer than a regular display because it would be less susceptible to cracks than glass."
As for the issues with Indium tin oxide, "all technologies used in electronics evaluate different chemical and material combinations, and we're likely to see continued innovation in these areas," McGregor remarked.
The materials in OLEDs degrade when exposed to air and moisture, so they must be encapsulated. In regular OLEDs, the organic layer is sealed between layers of glass. Methods of flexible encapsulation, however, generally don't work as well as glass.
Competition Is Fierce
Manufacturing problems have delayed the advent of flexible displays. Sony showed off a flexible OLED display in 2010, while Samsung demoed its flexible OLED display at last year's Consumer Electronics Show.
"It's my understanding that Samsung had earlier announced that they would bring a flexible product into the market by the end of this year [and this] has been pushed out to the first half of 2013," Jakhanwal told TechNewsWorld. "Samsung is working on resolving the issues."
Meanwhile, the South Korean government has chosen Samsung rival LG Electronics to lead a project to develop flexible OLED displays.
Samsung's development doesn't necessarily mean that twisting, flexing phones are right on the horizon, though they could be formed into shapes using the screens.
Flexible screens "have been the holy grail for a while, but you'll also need flexible batteries, circuit boards, and chips," Carl Howe, research vice president at the Yankee Group, told TechNewsWorld. "It's a tough job."
"Even when a new technology is developed, it usually takes three to five years to make it to production and another three to five before it has mass-market adoption," McGregor said. "This seems to hold true for just about every new technology except 3D, which continues to fail."