Printed electronics and PV: A love story

by Michael A. Fury, Techcet Group

December 7, 2010 – The IDTechEx combined Printed Electronics USA 2010 and Photovoltaics USA 2010 opened December 01 in the Santa Clara, CA convention center with ~1200 registered and walk-in attendees. This international event now has regular counterparts in Europe (Dusseldorf in April) and Asia (Tokyo, June), and has done a good job establishing its identity as the go-to meeting for printed electronics users, designers and both equipment and materials suppliers. This is the third year I’ve attended, and I’m pleased to see the organic growth around a base of regulars. The addition of photovoltaics to the printed electronics event is a good move in terms of capitalizing on the overlap of the two technologies, but the parallel session format does add to the level of Heisenberg frustration when you can’t be in two places at once.

A morning of keynote addresses filled the large auditorium to capacity before the crowd split up for the parallel tracks.

Click to EnlargeJeff Duce of Boeing opened the meeting with a discussion of printed electronics (PE) in aerospace. Survivability is key in this industry. Challenges include frequent wide temperature swings between ground and flight levels, and the risk of exposure to hydraulic fluids, which he says are some of the most corrosive chemicals in widespread use. Another big survivability challenge is lightning strikes — on average, every plane in the fleet is struck by lightning once per year. Weight reduction is critical, and PE harnesses are pre-wired into the fuselage modules before assembly; we’re talking about big harnesses. The 747-8 also uses a PE sensor system throughout the structure to monitor stress and damage.

Eric Penot of international advertising firm JCDecaux talked about the many uses of PE for advertising, present and future. In their business model, they sell advertising space; in some cases, this requires them to create the space on which to place the advertising, such as street furniture and concession facilities. LCD and plasma screens used in subway systems require special designs to make them resistant to brake dust, the fine iron particles from subway brakes that become airborne and magnetic and are attracted to displays, causing blurry images. Very large displays have a 6mm pixel pitch — that seems huge, but the human eye stitches it together quite nicely. Future specs for large displays include a contrast >1000, pixel pitch 1.5-3mm, 30 frames/sec for indoor use (2sec for a picture change outdoors), $100/ft2, and single display units >20ft2.

Greg Nungester & Luis Rodrigo Piñeiro of Crayola brought an unexpected player to the agenda. In addition to being the largest art supply and stationery company, Crayola is also the fifth largest toy company in the world. For cost and disposability reasons, PE plays a huge part in their product strategy. The company does 480 million linear feet of functional printing per year, which includes all manners of PE and excludes graphic art. Oddly enough, during their presentation the room was filled with the scent of crayons; we were assured that this is a psychological association of scent with pleasant memories of coloring, and not due to any gas emissions. The effect was real, and striking.

Marc Vermeersch of Total SA Gas & Power has a diversified investment portfolio in several photovoltaic (PV) technologies around the world. He considers organic PV (OPV) the most significant disruptive solar technology of the last 20 years. The cells are flexible, lightweight, less sensitive than other technologies to low intensity and off-angle light, and provide adequate efficiency for the cost. The efficiency improvements seen in other PV technologies over the past 20 years can reasonably be anticipated for OPV as well. The abundant raw materials are amenable to high-speed and high-volume manufacturing.

Michael Londo of MWV Packaging talked about some emerging smart packaging concepts. Healthcare is a target market, such as an RFID-enabled blister pack for pills that tracks the time of usage, or emits a reminder if a scheduled dose is missed. The clamshell packaging we all know and love to hate was demanded by retailers who wanted a means to deter easy concealment and theft — which is why you can’t open the cursed things without obvious tools and a dance of frustration. These beloved clamshells result in 300,000 emergency room visits per year. But hey, our products are safe!

Another side of PE applications was shown by James Zunino of US Army ARDEC (Army Research, Development and Engineering Center). The Army utilizes commercial powders and inks in their prototyping and volume production. However, they also operate their own nanoparticle reactor facility at Picatinny Arsenal in NJ, the only one of its kind in the world. Weight reduction is an obvious driver for infantry equipment of all kinds — on the Apache helicopter fleet, a weight reduction of 4lbs translates to $2B in annual fuel savings. (At this point, I refer the reader to recent news articles about the physical fitness of our recruits.)

Mike Woodhouse of NREL put things in perspective with an economic analysis of PV for addressing the global energy demand. (Hint: we need more.) Global consumption in 2004 passed the 15TW mark; in 2050 demand is projected to be 30TW. Surprisingly, the total cost of manufacturing and installing is comparable for the US, Malaysia, and China, thanks to tradeoffs between automation with capital investment and cheap manual labor. US module costs have dropped 50% in the last 2.5 years as volumes increase and PV infrastructure continues to develop.

Vivek Subramanian of UC Berkeley wrapped up the keynote sessions with a look a sensors for smart packaging. PE is an attractive technology because it requires no lithography and no vacuum processing; it is additive, not subtractive. Short lifetime, disposable printed displays are being developed for real-time labeling, which enables price reductions on products as expiration dates approach (currently it is cheaper to dispose of marginal product than to manually re-price each item). Previous electronic nose sensor technologies have failed because of false positives due to the complexity of most test environments. Inexpensive PE sensors, each tuned to a different compound, can be used in concert for pattern recognition across many sensors simultaneously, more like the way a nose works in nature. In a particularly clever program, Subramanian is using the dewetting properties of ink in collaboration with Dimatix to inkjet sub-resolution features onto patterned substrates.

David Mitzi of IBM Watson talked about a family of high efficiency thin film PV based on solution deposition of chalcogenides from hydrazine (N2H4) solutions using abundant elements. Talk about fun chemistry! Among the benchmark efficiencies demonstrated are: CuInGaSSe 14.7%; CuInSSe 12.2%, which is comparable to vacuum deposited material; and CuZnSnSSe 9.7%, which is the current world record for a solution-based thin film. Zn is not soluble in hydrazine, so Zn powder is added to a solution of the other components and reacts in situ to form a nanoparticle slurry. This is not the first time IBM has dabbled in slurry.

Prashant Mandlik of Universal Display Corp. is taking phosphorescent OLEDs from display pixels to lighting panels, which places a huge demand on uniformity of materials and electrode resistance because the eye is so sensitive to variations.

I walked in at the end of a presentation by Walt Bonneau of Cubic Security Systems on PE in the transportation industry, just in time to hear him say that one reaction to the airport backscatter scanners is the emergence of privacy underwear made with titanium threads. He didn’t say if the product carried a disclaimer for lightning strikes.

Tobias Jaenchen of Printechnologies made a new product announcement for Aircode Touch: a printed ID tag that can be read by and iPhone and other touchpad devices. The tag consists of aluminum ink that can be under the top graphic art layer of the packaging. Merely holding the product up to the touchpad allows it to be read by the software application, and the information processed as the application requires. This replaces uncommon RFID or barcode readers with a ubiquitous device that is available to the consumer as well as the supplier. It is expected to become a low cost alternative to RFID NFC (near-field communication). 3M Ventures invested in the company earlier this year.

The conference also included five short courses on November 30: an introduction to PE, thin-film PV, printing technologies, materials, and an Investment Summit.

Michael A. Fury, Ph.D, is senior technology analyst at Techcet Group, LLC, P.O. Box 29, Del Mar, CA 92014; e-mail [email protected]


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