05 Feb 2009
Flexible active-matrix OLED displays could change the face of communication devices.
Flexible mobile phones or GPS devices that can be worn like a watch belong more to the realm of science fiction than fact you might think. Now, thanks to a prototype communication device worn on the wrist, this futuristic technology looks set to become reality giving a whole new meaning to the phrase 'Hands Free' technology.
The prototype device is a four-inch flexible OLED display housed in rugged packaging that can be wrist worn or wrist mounted. Developed and manufactured by Universal Display Corporation (UDC), New Jersey, US, in collaboration with LG Display and L-3 Display Systems, the device enables the wearer to view real-time video and graphics.
"One of the unique features of OLED technology is that it is compatible with flexible or conformable substrates unlike LCDs which really don't behave or perform very well if built onto a flexible or bendable surface," explained Janice Mahon, VP of technology commercialisation at UDC. "This particular prototype was meant to show one of the potential form factors in which a flexible OLED could be used."
The display itself is made from UDC's active-matrix OLED (AMOLED) technology and is built on metal foil instead of conventional glass substrates making it lightweight, flexible and conformable. Adapted from the company's phosphorescent OLED technology, small-molecule phosphorescence is also said to improve the AMOLED's power consumption by a factor of four in comparison with other fluorescent OLED materials.
UDC has just received a further $1 089 600 in investment thanks to a Small Business Innovation Research (SBIR) Phase III contract issued by the United States Army Communications Electronics Research and Development Engineering Center (CERDEC) to continue developing the prototype.
The device is seen to have great potential in military field communications where large, bulky glass-based light sources and displays are heavy and consume a lot of power. An extremely lightweight mobile phone or GPS worn on a soldier's wrist is a much more practical alternative, freeing up both hands for other work.
This is just one programme in UDC's ongoing research in OLED technology and applications. The company is also investigating ways to achieve true flexibility in which a display can be rolled or flexed repetitively without loss of performance.
Other challenges involve the issue of packaging the organic materials that are susceptible to degradation from oxygen and moisture. Glass-based displays can use another piece of glass as a protective coating on top of the OLED with a perimeter sealant. This is not a viable option for flexible or conformable displays. Research is underway to find suitable coatings that are impermeable to oxygen and moisture while maintaining the OLED's features.
Looking to the future, UDC is also considering making its flexible screens touch compatible, a facility currently seen in products such as iPhones. While integrating a touch component into a flat display is straightforward, new challenges arise with integrating touch components onto a display that is conformed or flexing.
Caryl Richards is features editor of Optics & Laser Europe magazine.