Huge increase in printed electronics toolkit
2009年6月25日 Dr Peter Harrop
This year has already seen a huge increase in the choice of electronic components that can be printed or are compatible with printing in that they are thin, flexible and can support further printed circuitry on top.
There have even been new types of components appearing that will greatly enhance the functionality of printed circuits. For example, a memristor is a fundamentally new component for electronic circuits that industry scientists developed in 2008 and created in thin and flexible form at the National Institute of Standards and Technology (NIST) in the USA in 2009. The NIST invention was initially seen as flexible low cost memory to compete with the Thin Film Electronics but it has now been shown to act as a memristor and this is opening up new possibilities.
The memristor is a component theorized in 1971 as a fourth fundamental circuit element (along with the capacitor, resistor and inductor). It is a resistor that changes its resistance depending on the amount of current that is sent through it and retains this resistance even after the power is turned off.
InkTec recently printed ferroelectric non-volatile memory reel to reel and with high yield: it was developed in Sweden by Thin Film Electronics. Other advances include thin flexible lasers demonstrated at Cambridge University CAPE in the UK, flexible thin supercapacitors from CapXX Australia and thin flexible thin Supercabatteries from Nanotecture in the UK. The latter combine the properties of a battery and supercapacitor and are intended to outperform supercapacitors. Some are well under one millimeter thick.
Alternatively, thin fuel cells have been developed that are intended to outperform even lithium thin film batteries. German researchers at the Technical University of Berlin and the Fraunhofer Institute for Reliability and Microintegration IZM in Berlin have developed a fuel cell that weighs only 30 grams and has an output of 12 watts - giving a power density of 400W/kg that has only previously been seen in much larger systems.
First intended use is a mini helicopter powered by very light fuel cells that could find people trapped in earthquakes.
As well as being used in contaminated areas, the fuel cell could be used as a charging point for laptop computers and cell phones. The researchers reduced the weight by using very thin, planar fuel cells. IZM team leader Dr. Robert Hahn explained, "We have replaced the metal plates by lightweight plastic spacers." The researchers have no need for an additional pump to provide an adequate air supply. The wind generated by the helicopter's rotor blades goes directly into the air vents.
The scientists had to devise a solution for the hydrogen supply, too, as a conventional pressure tank would be too heavy for the helicopter. "We have built a small reactor containing solid sodium borohydride. If we inject water, this produces hydrogen," continued Hahn. A prototype of the lightweight fuel cell has already been built by the team and they expect the mini-helicopter to take off with it later next year. CEA Liten in France has also announced a thin film fuel cell.
Metamaterials are nano-patterned films and other structures that bend the radiation targeted, be it light, infrared, terahertz or microwaves. They will lead to many previously impossible optical and electronic components so funding is increasing for work on these exciting new components. In addition to ongoing work at many US and German universities and the pioneering work at Imperial College London UK, Professor Zheludev of the University of Southampton UK has now received substantial funding to work in the arena.
Rapid change in market structure
The market for printed and potentially printed electronics in 2009 is as shown below. However, well within the next decade, it will become predominantly printed and flexible and totally new applications will have opened up including the huge potential for transparent electronics. In 20 years, it will be over $300 billion.
Market for printed and potentially printed electronics in 2009
Source: IDTechEx report "Printed, Organic and Flexible Electronics Forecasts, Players & Opportunities 2009-2029.
Unbalanced supply chain
Currently the supply chain is typical of new technologies, with too little user pull but that is changing. Indeed, IDTechEx has many new clients in 2009 that are in consumer goods, electrical goods and other sectors that eagerly seek to adopt printed electronic products and capabilities.
Unbalanced supply chain for printed electronics
Source: IDTechEx report "Introduction to Printed Electronics."
Many new processes.
New processes are also driving new component designs, an example being flexible copper indium gallium di-selenide CIGS photovoltaics. Whereas Nanosolar and others print these and are seeking to scale up their processes and improve efficiencies, Ascent Solar Technologies, Inc a developer of state-of-the-art, flexible thin-film photovoltaic modules, recently announced a monolithically interconnected 5 meter long flexible light weight module on a polyimide substrate using the company's unique 1.5 MW roll-to-roll manufacturing line.
The lightweight design is expected to allow the module to be hand-carried if needed, as opposed to glass modules that have to be hoisted with a crane across rooftops. The module can produce 123 watts under standard test conditions with an aperture area efficiency of 9.1 percent.
This length is a baseline for the company's development of large area flexible building integrated photovoltaic (BIPV) products with its strategic BIPV partners.
"This is the largest monolithically interconnected CIGS (copper indium gallium di-selenide) module on polyimide and may be the largest of any CIGS module regardless of construction," said Ascent's Prem Nath, senior vice president for product operations, in a news release. "The size and efficiency of this module make it a breakthrough for the emerging opportunities of flexible CIGS photovoltaic modules."
Ascent's Director of Investor Relations Brian Blackman said he knows of one other small European company working in this area that's still in the research and development phase. Production is expected to start at the more than $100 million facility at the beginning of 2010.
On the other hand, Innovalight's facility in Sunnyvale, California uses touch-less inkjet printing of silicon-ink, which the company claim can halve the number of costly manufacturing processes required to produce highly efficient solar cells. It partners with OTB Solar. Nanogram focuses on using its own doped silicon inks on its 35µm multi-crystalline silicon technology (mc-Si), called SilFoil™. It claims that the cost in volume of these photovoltaic cells can be significantly cheaper than conventional wafer based silicon cells, easily able to compete with the cost of CIGS or CdTe in similar volume, while offering a much higher efficiency compared to either of those technologies.
Another of NanoGram's priorities is on transistors made with printed silicon semiconductors and one application for these will be display backplanes. Within a few months of development, the company has passed the mobility of amorphous silicon, and believes that mobility in the range of >100cm2/Vs is achievable, although for display backplanes that is not needed.
While the sintering temperature of the deposited transistors is confidential, IDTechEx note that Teijin, the plastic substrate supplier, is a partner of NanoGram involved in a joint development agreement (JDA) to develop silicon inks for flexible electronic applications. In addition, NanoGram investors include a wide range of companies with a number from Japan, given that one of the largest applications will be display backplanes.
Unique conference in Tokyo
The latest advances will be fully aired at the major event Printed Electronics Asia in Tokyo 30 September to 1 October. It consists of a conference, exhibition and optional visits to local centers of excellence including Toppan Printing, Toppan Forms and Dai Nippon Printing. There are optional Masterclasses as well.
Within the lineup of best-in-class speakers from all over the world, there will be T-ink of the USA that has sold printed electronic products to Hallmark, Toys"R"Us, Caterpillar, Sears, Kent cigarettes and many other famous brands.
Imperial College London will cover printed electronics for medical diagnostics and PARC USA will reveal printed electronic sensors for mild brain injury. Power Paper of Israel, which has licensed printed electronic products to Hasbro, Estee Lauder and others, will describe its printed iontophoretic skin patches and Bridgestone of Japan will give the latest on its electrophoretic film that will compete with E-Ink.
New forms of printed transistor where the paper substrate is the gate will be covered by Professor Elvira Fortunato of the New University of Lisbon Portugal and Dr Flora Li of the University of Cambridge UK will explain her low temperature deposition of indium zinc oxide based transistors.
Samsung describes oxide transistors driving AMOLEDs. Dr Hideo Hosono of Tokyo University will also cover inorganic printed transistors whereas the different printed organic transistors of Toppan Printing and Sony will be the subject of other presentations. Fujitsu and NEC will cover carbon nanotube and graphene composites for printed electronics, two speakers from Japan will deal with printing RFID while Mitsubishi and many others will explain their latest process improvements and inks. IDTechEx has a new report on this called Carbon Nanotubes and Graphene for Electronics Applications: Technologies, Players & Opportunities.
New thin film sensors and batteries from Australia, organic, DSSC and other photovoltaics, wide area stretchable displays, new OLEDs, Liquavista electrowetting displays, printed memory and printing those essential barrier layers - it is all here. For more information on this event, visit www.IDTechEx.com/peAsia.