Partnering with E Ink Corp. and DuPont Teijin Films, researchers at Arizona State University’s Flexible Display Center (FDC) have created what they are dubbing the world’s first active-matrix display on a flexible substrate with a touchscreen (Fig. 1). Also heralded as a revolutionary breakthrough, the glass-free display is reportedly the first of its kind to enable real-time user input.
According to the FDC researchers, the display teams their low-temperature thin-film transistor (TFT) technology with DuPont Teijin Films’ Teonex polyethylene napthalate (PEN) films and E Ink’s Vizplex ink laminate. The trio of technologies allows the formation of active-matrix electrophoretic (a.k.a. electronic paper) displays while the touchscreen comes by way of integrating an E Ink/Epson lowpower display controller.
FLEX DISPLAYS PAST AND PRESENT Flexible displays are still a bit of a novelty, but nothing new. In December 2005, Samsung unveiled what it called the largest flexible LCD, a 7-in. diagonal component with a resolution of 640 by 480. Samsung’s display replaced the typical glass substrate with a flexible plastic.In May 2007, LG Philips created what it called the world’s first 14.1-in. flexible color display. The display was the result of arranging TFTs on a flexible metal foil instead of glass (Fig. 2). Described as E-paper, the color display measured approximately the same as an A4 sheet of paper. In conjunction with a color filter on the plastic substrate, it employed electronic ink from E-Ink Corp. to produce up to 4096 colors and a view angle of 180°.
FLEXING FOR THE FUTURE “Pen and touch input has become the preferred user interface in many portable electronic devices,” said Michael McCreary, VP of research and advanced development at E Ink. The FDC flexible touchscreen display supports real-time user input either by stylus pen or by touch. It consumes power only when the electronic paper is activated. Once sketched or touched into the display, data can be stored in some form of memory or transmitted wirelessly.“The ability to incorporate the flexible touch feature into the display will enable a host of new applications that require shatter-proof displays,” he said.
“We believe successful deployment of flexible touchscreen technology can stimulate a number of applications that will allow military and ultimately other users to input, store, or transmit real-time data from remote locations using ultra-low-power displays that are rugged, sunlight readable, lightweight, and thin,” explained FDC director Nick Colaneri (Fig. 3).
Those other applications are fairly obvious, i.e., any design requiring a display to fit on a curved or odd-shaped surface. With the penchant to shrink every component in sight, we may even see these flexible displays performing as labels on everything from medical-prescription bottles to clothing.