This morning in Eindhoven, the Netherlands, Philips Research and New Venture Partners announced the creation and funding of their first spin-out - Liquavista B.V. The spin-out was created to commercialize the market opportunities for electrowetting (EW) displays, a technology invented by Bob Hayes and Johan Feenstra at Philips Research, and first announced at the International Display Research Conference held in Phoenix in 2003. Liquavista is initially targeting applications in the mobile display market.

Ken Werner
Senior Analyst and Editor
of MDTV Retailer

Wait a minute. Doesn’t LCD technology - really a family of LCD technologies - currently dominate the mobile display space? Yes, and isn’t there a very interesting challenger (active-matrix OLED) that is certain to make a major impact in that space next year? Yes, again. So, given all that, aren’t there major barriers to entry for any new display technology in the mobile-display arena? You bet.

So let’s ask the question that should be asked of any new display technology: Does it do anything that existing technologies can’t do? And in this case, the answer is actually yes.

From the beginning, Hayes and Feenstra have described the special characteristic of EW display technology as its very high reflectivity. That means that it can be used in many outdoor and indoor settings without a backlight and still deliver bright images. It also implies excellent sunlight readability, something that neither LCD nor OLED has, although improvements are certainly being made.

In addition, EW has a simple structure, uses very little power, switches quickly enough to show video easily, uses standard amorphous-silicon backplane technology for its pixel switches and is compatible with standard LCD driver ICs. And the technology is like nothing else being used for displays.

Briefly, a single pixel of an EW display consists of a reservoir that can be as small as 1/5 of a millimeter across, or less. The "floor" of the reservoir is transparent glass or plastic and is covered with a very thin layer of fluoropolymer. A small drop of colored oil is placed in the reservoir and covered with water (remember, oil and water don’t mix!). The reservoir is covered with another glass or polymer layer containing an electrode.

With no voltage applied, the oil spreads out in an even layer on the floor of the reservoir. Ambient light shines through the water and colored oil, reflects off the white background and through the oil and water again. The pixel has the color of the colorant in the oil, which can be quite saturated. Given the intense activity of the dye industry over the last couple of centuries, a wide variety of stable colorants are available.

When an appropriate voltage is applied, the system energy is no longer minimized by having the oil spread evenly over the floor of the reservoir. Instead, it is minimized by having the water cover the maximum area possible, so the oil beads up into a corner of the reservoir. Now, light shines directly through the water and reflects off the white background. In this state, the overall display can reflect 70% of the incident light, which is considerably more than any other display technology (except paper).

Power consumption is also considerably less than any other video display. A full-color EW display consumes less than half the power of a Qualcomm iMoD MEMS display, says Liquavista.

So, there is good reason for Liquavista to continue the development of EW display technology. That’s not to say that the road to commercialization will be smooth or that finding customers will be easy. But this is a technology that can’t be dismissed.

You can see EW’s current state of development at the SID show in San Francisco in early June and at FPD International in Yokohama in October. We will be there to check it out.