- Smart Electrofluidic Displays Best LCDs
- Organic materials were once touted as the next generation of displays—for instance, Apple is rumored to be introducing a new iPad sporting an OLED display later this year. Unfortunately, the billion-dollar cost of starting up new flat-panel manufacturing lines has display makers extending the lifetime of their existing LCD lines. Now researchers are touting a way to convert LCD manufacturing lines for next-generation electrofluidic displays that are brighter, faster and lower power than LCDs or OLEDs.Before the recession, liquid crystal displays (LCDs) were touted as a legacy technology that would slowly give way to organic light-emitting-diode displays (OLEDs). However, the consumer spending slowdown has instead led to LCD manufacturing overcapacity, prompting Sony and Toshiba to scrap plans for new OLED lines. To the rescue is a new electrofluidic display technology that offers displays that are brighter, faster and lower power than LCDs—and yet can be manufactured by retrofitting existing LCD manufacturing lines.
The new electrofluidic display technology uses the same sort of inorganic manufacturing materials as LCDs, allowing their manufacturing lines to be converted over, rather than being made obsolete by organic LED displays. But the biggest advantage of electrofluidic displays is that they require zero power to maintain an image on the screen. Both LCD and OLED displays typically use either fluorescent or light-emitting-diode (LED) backlights for easy reading, but electrofluidic displays instead reflect ambient light.
E-Ink already manufactures its zero-power electrophoretic display used by Amazon's Kindle, Sony's Reader, Barnes & Noble Nook and every other e-reader. Unfortunately, electrophoretic displays are only monochrome today, plus they are too slow to display video and other fast-changing content. Electrofluidic displays, on the other hand, are just as bright and low power as electrophoretic displays, but are as fast and colorful as LCDs.
To unite the best of both worlds, University of Cincinnati Professor Jason Heikenfeld enlisted the support of DuPont and Sun Chemical to help develop its electrofluidic display, which the university has now licensed to startup Gamma Dynamics (Cincinnati). Created in the Novel Devices Laboratory at the University of Cincinnati, Gamma Dynamics is currently targeting the technology first for automated price tags on grocery store shelves and then for cell phones, e-books and touch-screen tablets.
University of Cincinnati Professor Jason Heikenfeld, at left, and doctoral candidate Shu Yang demonstrate how much brighter their electrofluidic display (right) can be using incident light compared to a normal backlit LCD.
Like an LCD, the interior layer of the electrofluidic display is liquid. However, unlike LCDs, the fluid is confined to pixel-sized reservoirs. When a voltage is applied to a pixel, the colored fluid is pumped into the pixel in front of a mirrored electrode, thus reflecting that color of light.
To turn the pixel off, the colored fluid is pumped back into reservoir, thus turning it off. In either case, the pixel retains its state indefinitely when the power is turned off.
Pigment fluid can be electrically attracted to the top cavity (making a color) or retreat to below the central mirror (making white), amplifying ambient light in an exceptionally bright display.According to the researchers, under normal ambient lighting conditions, electrofluidic displays are even brighter than LCDs and OLEDs, extending the battery of the devices using them compared with using backlights that run batteries down in a matter of hours.
For mobile applications such as cell phones and touch-screen tablets, side-mounted LEDs can provide enough light to illuminate the electrofluidic display at night or in darkened rooms.
A University of Cincinnati researcher holds prototypes of its electrofluidic display, which has been licensed to Gamma Dynamics (Cincinnati).