The Long, Flexible Road Ahead

Frederic Zenhausern knows that there is plenty of difficult work ahead for himself and his colleagues. Zenhausern is technical director for the new ASU-Army Flexible Display Center. Developing the technologies needed to take today’s rigid and heavy displays and transform them into lightweight, flexible, low-power devices is not going to happen in a nano-moment. But it needs to happen fast.

“There are multiple technical challenges to making these devices fully flexible, lightweight, and extremely low power,” Zenhausern explains. “One of the biggest challenges is creating a reliable supply of display quality flexible substrate material that is impermeable to moisture and oxygen.”

A second major challenge is to make sure all of the display materials are themselves flexible, says the ASU scientist. Brittle materials are no good. They can make the display unit crack. The entire thin integrated display needs to be held in one piece when it is flexed.

Researchers are working to improve the lifetime of the final device. It must be able to be folded over and over again without cracking and without altering the display’s full color efficiency. The same must be true of display resolution and all of the other typical performance functions, Zenhausern says. The high-tech home of the FDC is well suited to development of flexible displays. The facility once was Motorola’s flat panel display headquarters at the ASU Research Park.

FDC researchers have already made progress. They have established a fully operational 6-inch wafer-scale thin film transistor (TFT) pilot line, and a leading edge organic light-emitting diode (OLED) R&D laboratory, led by ASU expert Ghassan Jabbour. Additional capabilities in design, process tool development, and display assembly will be provided by FDC member companies leasing space in the facility.

The R&D team includes scientists and engineers such as David Allee, who leads the TFT backplane electronics design and development. Jabbour leads the efforts in OLED technology. Terry Alford studies new substrate materials and characterization methodologies.

The engineering team is led by Shawn O’Rourke. They provide industrial expertise in designing and setting up the large-scale pilot line that could create new business opportunities in display systems for ASU.

Working with government and industry partners, researchers at FDC will start with small rudimentary displays about 2.5 inches in diagonal.

By the end of 2005, Zenhausern says, the center will have prototypes of the first limited flexibility 4-inch diagonal concept devices. The overall goal is to continue improvements to display functionality with increases in size, reliability, and flexibility. Final display devices will range in size from 10- to 17-inches diagonal.

Initially, the displays will be monochrome. They will be developed into full color.

In terms of flexibility, the initial rugged displays will evolve into conformal displays, then rollable, and finally into foldable devices. In parallel, the center will develop the associated manufacturing processes required to efficiently and cost-effectively produce integrated flexible display demonstrators.

If all goes well, Zenhausern says the FDC will have these demonstrators sometime in 2009. —Skip DerraEngineering and Technology: Computer Science | Engineering and Technology: Materials Engineering