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Flexibly speaking about printed electronics: Final musings from the Flex conference |
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Jan 29, 2008 at 01:15 PM |
Before I move on to other topics, here are a few final musings and observations from the 7th annual USDC Flexible Electronics and Displays Conference, held last week in Phoenix.
Roll-to-roll manufacturing is already here, but it's also a long way off: For many, the idea of using solution-based processing (AKA pure printed electronics) on gravure, Web-coat, or flexographic manufacturing equipment, continuously producing kilometers' worth of flexible devices at modest price points, is the proverbial holy grail.
Simple, low-cost display and RFID devices are already coming off R2R or hybrid lines, while the likes of Uni-Solar and PowerFilm have been cranking out megawatts of thin-film amorphous-silicon photovoltaic cells on flex foil for several years.
But when the discussion turns to high-information content, more complex (and costly) items---such as large-area, high-resolution-color active-matrix TFT displays, polymer OLEDs by the sheet, high-end e-paper, and other memory or logic devices---volume manufacturing remains a work in progress.
While the materials side has come along quite nicely, with at least a dozen key suppliers, big and small, providing process-enabling chemistries, many people I spoke with pointed to the relatively immature capital equipment sector as a weak link in the development of advanced R2R manufacturing. Although Northfield Automation, Tamarack, Applied Materials, Precision Process, and other tool suppliers are actively involved in the printed/flexible electronics space, more intense equipment and process development needs to take place.
Ongoing R&D work at ITRI's flexible electronics pilot line in Taiwan, the Center for Advanced Microelectronics Manufacturing (CAMM) facility coming together at SUNY Binghamton, the Flexible Display Center (FDC) at Arizona State University, and the systems-on-foil (note new buzz-phrase) projects at the Holst Centre in Eindhoven, the Netherlands, as well as work at Motorola, PowerFilm/HP, Soligie, and other companies, will be essential in moving the R2R tool infrastructure forward.
E-paper comes of age. "This is the beginning of something very big and it's actually taking off now," E Ink's Mike McCreary told conference attendees. "The ink performance required for success in electronic publishing has been achieved in volume production." Electrophoretic reflective bistable displays, employing the company's Vizplex microencapsulated electrophoretic ink, are running through more than a few factories. Although still in its early stages in the flexible display realm, the company's e-paper technology has been integrated into several different reading devices, including Amazon's Kindle and Sony's e-Reader.
More commercial electronic paper displays (EPDs) will be released this year and in early 2009, with flexible EPD TFT displays from Plastic Logic, Polymer Vision, and PVI/Phillips all coming out soon. Advanced inks for larger-area, front-plane layers, wearable electronics, and e-signage applications are not that far from commercialization either, according to the company's VP of R&D. McCreary also credited the rapid evolution and maturation of E Ink's "strategic partner ecosystem" with the escalating growth in the product space.
E Ink's success, and the commercial devices that its nanofilms are already enabling, are an example of what FDC's Greg Raupp had in mind when he said, "five years ago, this was an artists concept-dominated conference; now, people have actual products." Still, many flex devices aren't quite quite ready for prime time, but...
...Cool stuff's still happening in the labs: Jack Hou of ITRI generated alot of interest with his discussion of the overall flexible electronics program at the Taiwanese research center, as well as details of how they are fabricating "organic inverters based on polymer transistor arrays on plastic substrates" (which use hybridized and traditional TFT and inkjet printing techniques). Before delving into the details of the polymer inverter, he cited "recent progresses" (sic) accomplished at the lab. Although nonvolatile memories on polymer, polymer diodes, and flexible recitifiers (a sort of printed antenna) are admittedly worthy of a raised eyebrow or two, my favorite of the bunch was the "paper speaker."
Apparently the ITRI team has managed to print an audio speaker on a very thin paper substrate. When asked how well it worked, Hou said it had "good sound except for the bass frequency." Well, that's a pretty big "except." Until they get that bottom-end of the sonic spectrum thumping, don't expect many audiophiles, dancing fools, or subwoofer aficionados to pay much attention. Despite the initial shortcomings, it's a pretty cool gizmo-prototype.
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