Foldable, Bendable And Bright: The Future Of Displays


Neil Kane, Contributor

July 31, 2014

The desire for better display technology is insatiable. Foldable, bendable displays have been in our collective conscious for nearly a decade, but things are heating up and speeding up. A few months ago Apple acquired a stealth-mode startup called LuxVue that is working on new types of information displays. While we don’t know the exact rationale for Apple’s acquisition, another startup called X-Celeprint may have superior technology and is really the company to watch.

The details about LuxVue are sketchy, but we know that they had raised $43 million in venture capital from prominent Silicon Valley firms including Kleiner Perkins. As TechCrunch and VentureBeat have both reported, LuxVue makes micro-LEDs which have the following advantages over organic LEDs (OLEDs) and older liquid crystal display (LCD) technology:

  • Better battery life
  • Better screen brightness.

The biggest valuation jump for an early-stage company comes when they start shipping products and gain market traction. That LuxVue’s investors were willing to let them go prior to the hockey stick means either that Apple paid dearly for the privilege or LuxVue was facing a mountain of technical issues and/or needed a lot more cash than investors were willing to contribute (which wouldn’t happen if they were really onto something—money chases good deals). If anyone has any insight, please comment.

Apple confirmed the acquisition but hasn’t said what they intend to do with the LuxVue technology. iWatch anyone?

The technology that makes bendable displays possible, OLEDs, has been available for several years mostly in mobile devices (like my Samsung Galaxy S5) and is now being demonstrated in some high-end TVs as LG showcased just a few weeks ago. Recently Samsung showed off some concept smartphones based on bendable displays.

Apple’s acquisition of LuxVue leads me to think that the smart money is on micro-LEDs.

Back in 2009 Prof. John Rogers from the University of Illinois at Urbana-Champaign published a paper in Science showing how micro transfer printing could be used to make displays from micro-LEDs.

Micro transfer printing (µTP) is a method of, essentially, using a type of rubber stamp to pick up very thin strips of semiconductor material (as the “ink”) and place it somewhere else by “stamping” it. The advantage of this technique is that it allows you to put high performance semiconductor elements (such as gallium nitride (GaN)) onto substrates where they wouldn’t normally be compatible (like plastic). And you can place the stamp over and over thereby creating large areas of arbitrary shapes out of otherwise small, high performance components—in ways that are impossible or infeasible with traditional semiconductor manufacturing processes.

Rogers describes in the Science paper making displays out of micro-LEDs using transfer printing. The micro-LED displays had great battery life, were very bright and, due to the nature of µTP, could be made at low cost. The trifecta of low cost, good battery life and a scalable manufacturing platform while maintaining excellent performance comprises the display industry equivalent of winning eight gold medals in the same Olympic games. It’s a big deal, and Rogers may have delivered it.

X-Celeprint, a startup which Rogers co-founded, is using micro transfer printing and building/designing [demonstration] systems around concepts that will in his words, “Completely change the notion of an emissive display device.”

The video below, courtesy of X-Celeprint, shows the µTP process at work.

Rogers continues, “We envision displays as highly functional systems composed of large collections of microscale light emitting diodes and other semiconductor devices, manufactured using the techniques of transfer printing.”

If he’s right, and I wouldn’t be against him, he will unshackle the connection between the traits of a display backplane (like glass or plastic) and the semiconductor devices that make up the active display elements. By decoupling these two processes, many new form factors and application scenarios become possible—bendable, flexible, foldable, odd shapes, lightweight, and so forth. More to the point, µTP enables this capability very inexpensively and is exceptionally scalable technology. For more on the importance of the manufacturability of processes, see: Get the Manufacturing Right.

“In most cases inorganics outperform organics so there’s a performance advantage as well as a manufacturing advantage,” said Michael McAlpine, Assistant Professor of Mechanical and Aerospace Engineering at Princeton University.

µTP for displays creates the potential for unprecedented low power operation, unmatched speed and contrast ratio, and brightness levels that can allow easy viewing even in direct sunlight. Many other functionalities could also be included—the materials and assembly techniques allow essentially any kind of semiconductor device or sensor to be integrated directly into the display itself. The displays can be constructed on nearly any kind of material.

The potential is quite significant, and all of the technology pieces are now available.

“The significance of micro transfer printing is that it brings all of the performance and durability of inorganic materials to flexible and stretchable substrates. John is really the first person to do this by starting with wafer-based materials, which provides an unprecedented level of scale and uniformity,” McAlpine says.

Micro transfer printing is not just a way of making better displays, it’s an entirely new way of making sophisticated electronic devices. The brilliance behind µTP is that it can be used for so many other things: flexible solar panels, breakthrough medical devices and unfathomed entertainment concepts. Did Apple know about Rogers work when it acquired LuxVue?

Neil Kane (@neildkane) is the president of Illinois Partners which helps companies, universities and investors with innovation strategies and technology commercialization.

Disclosure: I did some consulting for another one of John Rogers’ startups, Semprius, at the time of its founding and earned some shares of stock which I still own.

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