Collin Arocho
18 February

After getting acquainted with electrowetting displays (EWD) in the Philips Research labs, Hans Feil and a few of his colleagues decided they wanted to dive deeper into the technology. Two decades and two spinoffs later, Feil’s Etulipa is ready to show what its fully colored and very low-power EWD technology can do.

It was some 20 years ago that Dutch tech giant Philips was developing a new electrowetting technology in the labs of Philips Research. Making use of the surface tension of liquids, electrowetting utilizes low voltage to control the liquid. By combining several cells filled with a transparent polar liquid and a colored oil that covers a hydrophobic surface, the application of the voltage then causes the oil to contract into a small droplet so that light can pass through the cell. This creates an optical switch, which when connected to a computer, can be opened and closed on demand creating displays capable of showing text, art, photos or even video.

However, after a few years of development, and with no real direction or ambition within the larger Philips roadmap, a group of engineers, including business development officer Hans Feil were ready to take the technology and spin out as a startup focused on further growing the technology. “By 2006, we had spun out of Philips and founded Liquavista and got to work diving deeper into the technology than ever before. At that time, the company had a real focus on electrowetting displays for application in mobile technologies. This, of course, was when Nokia was supreme in that market well before iPhones and smartphones.”

The principle of electrowetting: the application of a voltage causes a water droplet to deform. Credit: Etulipa

“At the same time, however, we were also attracting some attention from the automotive sector,” remembers Feil. “They were interested in applying the technology into rearview mirrors to provide information to drivers. But that application didn’t fit with our displays approach at Liquavista, so in the fall of 2006, together with another former Philips colleague, I started another electrowetting company called Miortech, with a focus on integration into the rearview mirrors.”

New architecture

Right out of the gate, however, the technology struggled to gain traction. The company was well funded, with investors like BOM and a few others, but the group found out very early on that the first-generation technology wasn’t going to cut it. Feil and his colleagues were going back to the drawing board. Feil: “We had some ideas of the changes that were needed, but that meant we were going to have to invent an entirely new electrowetting architecture. One with a much broader application that could be used in both displays and the rearview mirrors.”

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In the end, however, this young and promising technology just wasn’t quite ready. It turned out, integration of electrowetting into rearview mirrors wasn’t going to work. Because of light scattering at the edges of the oil droplets, it created a haze in the mirror. Developers could never quite achieve the clarity and sharpness they were after, which meant the technology didn’t meet the standards for that application. Instead, the group needed to refocus their efforts and move on in a different direction.

“It was unfortunate, but it was all part of the development process and we really learned a lot. After that, we went back and worked to really master the basic technology,” recalls Feil. “But even with the slow start, we knew we had a display technology with high potential – it was just a matter of finding the right path. We knew if we wanted to grow, however, we were going to have to be open and at some point, we were going to have to work with other experts and larger companies in the display domain.”

E-paper

With their new architecture and a better feel for the core technology, Feil and his colleagues decided that outdoor displays were the next step. The new mission of the team was to provide a form of communication, information or art, that could work in harmony with the environment. In April of 2013, after more than 10 years of development and with a specific focus, they started a new company called Etulipa. Renewed with energy, the team was eager to show the potential of their next-generation EWD technology and prove it could be a real game changer. Just a year later, in early 2014, US-based Daktronics – a world leader in LED video and sports scoreboards – saw the potential of EWD for its business and opted to join the group of investors and put their support behind the Eindhoven startup.

The updated technology combines small glass tiles consisting of 77 pixels, each measuring one square centimeter and holding roughly 400 cells filled with droplets of colored oil. By layering cyan, magenta and yellow pixels, the display offers full-color abilities – all connected and controlled by electronics and computers. Better still, this EWD technology offers unparalleled specifications in terms of power consumption and infrastructure demands. “Our solution is what we refer to as e-paper. Unlike large power-hungry LED displays, the EWDs are readable only through the reflection of the sun. Meaning it’s not relying heavily on any sort of backlighting. It’s like reading a book, but digitally and with the ability to be scaled to very large sizes,” highlights Feil.

By layering cyan, magenta and yellow pixels, the display offers full-color abilities. Credit: Etulipa

A typical LED display consumes some 350 watts per square meter on average and up to 800 during full daylight, which can make LEDs difficult to see, Etulipa’s electrowetting display, on the other hand, requires only about 5 watts per square meter during the day. At night, when adding a few LED backlights to help the EWD’s visibility, that power consumption rises to roughly 9 watts per square meter.

“Because of this ultra-low power consumption, these systems aren’t required to be connected into the grid, which is prohibitively costly, in terms of time, labor and construction. By simply adding solar panels and a few good batteries, the displays can be easily powered in any environment, hassle free,” depicts Feil. “That also makes our system’s mobility a differentiating factor. They can be set up anywhere, at any time, with little to no interruption.”

Launch

It was exactly these benefits and the potential that Etulipa’s system could offer that has garnered the company newfound interest. So much so, that its Taiwan-based manufacturer, United Radiant Technology Corporation (URT), which specializes in small LCD screens, decided to take a stake.

“The addition of URT and its investment was a big step for us. Not only did they offer expertise in display technology and manufacturing abilities, but they opened the door to others in that realm – potential customers,” says Feil. “In fact, it was through a collaboration with URT that we launched our first application of an electronic changeable copy board in South Dakota for Daktronics. Up to that point, the black letters on these white boards had to be changed manually, but we could offer an electronic version of that, while still consuming less power.”

Pleased with the results of the copy board, Daktronics saw that Etulipa was ready to launch, and they agreed to be Etulipa’s launching customer. The assignment: to outfit an existing bus stop on the busy Queens Boulevard in New York City, without having to do major construction to tie into the grid.

“This was a great start to show some of the capabilities and market potential of Etulipa’s EWD technology. It’s really expensive to connect to a grid, especially in New York City. Replacement of curbs, digging deep holes and a mass of wires already in place can be a costly headache,” depicts Feil. “But with our system, we could avoid all of that. We were able to launch our first commercial application in September 2020 and make good on our mission to provide valuable information and communication in harmony with the environment.”