rom today's liquid crystal displays (LCDs) and even organic light-emitting diode-based displays (OLEDs).
Consider the difference in power consumption. The flexible displays will consume 100 times less power compared with LCDs. Even OLEDs, which are two to three times more efficient than LCDs, can't match that kind of efficiency.
The center is focusing on electrophoretic ink-based displays that are extremely low power and flexbile, says Raupp. The displays have thin-film transistor arrays on specialty polymer and thin stainless-steel substrates and use electrophoretic ink (E Ink), among other technologies, to render the characters.
E Ink, from a Massachusetts Institute of Technology spinoff, is composed of tiny microcapsules, each of which has positively charged white particles and negatively charged black particles suspended in a clear fluid.
Once a polarized electric field is applied, the particles move to the top or the bottom of the microcapsule, depending on the polarity of the charge. Alternating between the white and the black particles helps render characters and images on the screen.
To form a display, the e-ink is printed on to a sheet of plastic, which is laminated to control circuitry.
An early prototype has a soldier holding a flexible PDA weighing just 13 ounces and featuring an E Ink frontplane and a low temperature amorphous Silicon TFT backplane.
Currently, the center is looking at two kinds of flexible displays: a reflective display (which relies on ambient light) known as a "zero power" version for its almost negligible power consumption and an emissive low-power model that emits its own light. In comparison, an LCD relies on backlight.
The reflective displays are the most promising as they only require power to switch the transistors in the pixel array to update the image and have no backlight so power for fixed image viewing is very low.
"We need to look at technology that is fairly far along in the path towards commercialization," says Morton.
It is also evaluating additional materials and manufacturing issues to get the displays into production devices, says Morton. It hopes to have them in limited field trials within the next two to three years, and is working with companies such as LG to commercialize the technology.
"Our goal is to speed development of the displays and make them available for commercial manufacturing soon," he says.