Apr 16 2009

Improving Flexibility

HP's flexible electronic displays offer new opportunities for e-books, e-readers and signage.

The first affordable, flexible electronic display was recently unveiled by HP and the Flexible Display Center (FDC) at Arizona State University. Plastic was predominately used to develop this new paper-like computer display, which makes the device portable and more energy efficient than most conventional computer displays. The creation of this high-resolution flexible display is a milestone for both HP and the FDC as it represents an opportunity to manufacture for the mass market.

According to the director of information surfaces at HP Labs, Carl Taussig, “The display HP has created with the FDC proves the technology and demonstrates the remarkable innovation we’re bringing to the rapidly growing display market while providing a lower-cost process. The SAIL [Self-Aligned Imprint Lithography] technology represents a more sustainable, environmentally sensitive approach to producing electronic displays.”

Flexible electronic displays are creating new developments and solutions in the global high-tech industry. The technology provides opportunity for a new generation of portable devices, such as e-books and e-readers.

E-readers have the advantage of being interactive. Searching for a word in a book or a manual can be a complex task without an index, and even with a good index it could be hard to find any word combination. An e-reader can easily search inside a text document, and some e-readers also allow adding notes using a touch screen, which extends their usefulness even further.

Vinita Jakhanwal, principal analyst at Small and Medium Displays, iSuppli, expects the flexible display market to grow from $80 million in 2007 to $2.8 billion by 2013. Jakhanwal also adds that the Flexible Display Center at ASU is a key participant in helping to develop the technology and manufacturing ecosystem to support this market.

The new flexible electronic display technology could be applied to electronic paper and signage. Mass production could enable the displays to be put to use in notebook computers, smartphones and other electronic devices at a much lower cost than conventional display devices. From an environmental standpoint, another major advantage is that these flexible displays use only 10 percent of materials utilized in current display production, saving the environment and creating lighter devices for our pockets.

The process of manufacturing the display starts with FDC producing stacks of semiconductor materials and metals on flexible Teonex Polyethylene Naphthalate (PEN) substrates. Using the patented SAIL process, HP patterns the substrates and consequently incorporates E-Ink’s Vizplex imaging film to result in an actively addressed flexible display on plastic. The Vizplex is a bi-stable electrophoretic imaging film, which allows images to be continuously displayed even when no voltage is applied. This considerably decreases the power consumed by the display allowing for reduced electrical costs and much longer battery life for portable devices.

The SAIL process was invented by HP Labs and was paramount to the displays’ success. The “self-aligned” element in this method is derived from the patterning information, which is imprinted on the substrate in such a way that precise alignment is preserved regardless of process-induced distortion. SAIL technology enables the manufacturing of thin film transistor arrays on a flexible plastic material in a low-cost, roll-to-roll manufacturing process. This allows for a more commercially continuous production, rather than batch sheet-to-sheet production.