February 18, 2011 -- The market for printed electronics will be over $55 billion in 2020, according to research by IDTechEx.
Earlier roadmaps for printed electronics have been almost entirely erroneous, says Raghu Das, CEO, IDTechEx. It is not primarily about cost reduction, nor is there a trend towards organic versions taking over most applications. Combining organic and inorganic chemicals is increasingly the way to go, adds Dr Peter Harrop, chairman, IDTechEx. It is no longer focused mainly on improving existing products. Printing electronics is targeting radically different consumer products. A new ten year roadmap for printed electronics shows changes of direction with the materials, components, circuits and resulting products.
Printed electronics materials
New materials include relatively low cost, non-toxic products with electronic and electric properties for light creation to sensing of specific gases and generation of power in various ways, says Harrop.
Das points out that the introduction of printable copper by several companies last year, including Novacentrix and intinsiq, has led to a race to replace silver inks, with their price instability, in some applications such as antennas and transistor electrodes and interconnects. The alternative approach of using less silver by applying nano silver inks is also gaining traction. Much further down the line are CNT, graphene and other conductors and semiconductors offering even better performance. Currently, Heraeus is leader in organic transparent conductive inks and allied products with its Clevios brand.
Many developers in East Asia now see organic transistors improving in cost and performance too slowly to be the best solution for many high-frequency circuits in consumer goods, adds Das. For display backplanes, zinc oxide based semiconductors such as InGaZnO are prioritized for commercialization about two years after organic ones. Inkjet printed OLED TVs, RF-sputtered zinc oxide backplane transistors, printed manganese dioxide zinc batteries, printed organic transistors on a plastic substrate, and other products are being released by major electronics companies.
Printing solids is valuable, or at least printing materials that can easily be turned into solids at low enough temperatures not to damage low-cost plastic film substrates, Harrop points out. He notes that nanotubes are increasingly put down in the form of printing inks for high speed and wide area coverage.
For deposition, screen and inkjet printing are the most widely deployed for printed electronics but flexo and gravure and occasionally fast letterpress are now encountered, Das asserts. Sometimes, using regular printing machines with minimal modification is in prospect. For example, organic photovoltaics and OLEDs are relatively straightforward to print but they need very good barrier sealants against oxygen and water ingress. Companies such as Henkel have new advances in this area.
Integrated systems printed roll-to-roll at low-cost render the possibility of having consumer goods as well as industrial electronic systems that are extremely compact and energy efficient, says Wolfgang Mildner, chairman of the board of directors, Organic and Printed Electronics Association.
Inkjet printing is being rapidly deployed for printing electrodes on solar cells, where non-contact deposition is desired because thinner solar cells are more fragile, Das adds.
Harrop says that much more sophisticated printing processes are being applied to next generation solid state batteries in such things as power tools and traction batteries for the electric car industry; even the electrolyte is deposited by print processes.
Flexible electronics applications in solar, semiconductors, energy storage
Samsung Electronics is prioritizing printed electronics in materials, production machines, and components and manufacturing processes. Panasonic is also seeking to deploy electronic printing much more widely, particularly for the filter and liquid crystal layers in LCDs, antennae, flexible keyboards, etc. Nokia is working on stretchable printed electronics. Oxford Photovoltaics, a company recently spun out from the University of Oxford in the UK, has developed new solar cell technology that is manufactured from cheap, abundant, non-toxic and non-corrosive materials and can be scaled to any volume. The Russians, Koreans and others are racing to make flexible color e-readers by printing both inorganic and organic layers and also composites. Large lithium-ion traction batteries can be printed for the booming electric vehicle market.
Making basic building blocks such as timers and energy harvesters with storage will be important. Consider the European FACESS project depositing a complete photovoltaic, power conversion and storage unit on a single plastic film. Army applications include printing energy harvesting layers such as the VirginiaTech CEHMS piezoelectric layers that convert movement into electricity.
GeorgiaTech has printed flexible transistor arrays using high-K inorganic gate dielectric with organic layers.
Researchers are creating a new type of solar cell designed to self-repair like natural photosynthetic systems in plants by using carbon nanotubes and DNA, an approach aimed at increasing service life and reducing cost.
IDTechEx event: Printed Electronics Europe in Düsseldorf, Germany, 5-6 April, http://www.idtechex.com/printedelectronicseurope10/en/
LOPE-C 2011 -- Large-area, Organic and Printed Electronics Convention in Frankfurt, Germany, 28-30 June, www.lope-c.com