Printed electronics (PE) has come a long way since its beginnings, and the pace of development has become more rapid in recent years. As a result, there is much optimism for the future.

To get a clear perspective on how the PE industry has grown, and what the future may hold, Printed Electronics Now had the opportunity printed electronics with two industry leaders – Andy Hannah, president, CEO and co-founder of Plextronics as well as vice chairman of OE-A’s North American operations; and David Fyfe, who served as chairman and CEO of Cambridge Display Technology, and now is a senior advisor, Sumitomo’s PLED business – who offer their insights into PE.

Printed Electronics Now: How has the printed electronics field changed in the past 10 years?

David Fyfe: Ten years ago, very few companies in the electronics segment had any experience of printing beyond desktop printers. A notable exception was Seiko Epson, which had built industrial scale machines up to Gen 4 scale and had piezo-driven print heads capable of delivering droplets of less than 10pl. However, the need to lay down electronic components by printing was becoming clear and in the first five years from 2000 there was tremendous progress. Printhead development by Dimatix and Konica-Minolta took the minimum drop volume head availability from 30pl to 10pl and even less. Litrex was purchased as a start-up spinout from Rastergraphics in California by CDT and Gen 2 and Gen 4 printers developed with accuracy of +/- 15 microns – over 70 machines have been delivered. The LCD industry jumped on the printing bandwagon in the middle of the decade as the glass size got to Gen. 5 and bigger. First the alignment layer was applied by printing instead of roller coating and then, largely unsuccessful, attempts were made to print the spacers between the sheets of glass in an LCD panel. Hitherto to Gen. 5, glass beads had been scattered on the glass to effect spacing. Finally, and again driven by glass size, color filter direct printing was used to print color filters which had been patterned by lithography. Success in this application was mixed.

At the same time, printing was being developed for printing of electronic components such as OTFTs (Plastic Logic), phosphors, interconnects, PCB components, RFIDs and batteries. Printhead technology advances and work to allow fine detail tracks to be laid down were at the heart of these developments and applications. Development continues apace with companies such as Kovio printing silicon transistors, PolyIC and Plastic Logic printing OTFTs using materials being developed by the likes of Merck, Sumitomo Chemical, Ciba and others, printed battery technology from Enfucell and printing services available from Soligie and others. Organic photovoltaics are on the verge of mass commercialization thanks to the efforts of pioneer companies such as Konarka and Plextronics.

Andy Hannah: We have been focused on printed electronics since 2004. In the early days of the industry, there was a focus on scientific experimentation. During the past five or six years, there’s been a constant shift toward commercialization. What we have seen in the OLED market is companies making investments in printing technologies, and they are now getting their early products to market. Samsung’s OLED device is a good example.

Printed Electronics Now: What are the advancements that have allowed these changes to occur?

David Fyfe: As mentioned above, simultaneous development of accurate printing equipment, low drop volume/increasingly accurate printhead availability and materials development, particularly the growing availability of nano-particle inks, have all been technology pushes, but equally important, applications which favored the use of low-cost, direct application printing over more traditional subtractive processes such as photo lithography. These include mass use of low cost RFID tags, patches to monitor body data and, very recently, applications of cosmetics and drugs by dermal patches, and also a growing interest in thin-form sensors for a wide range of applications from pregnancy testing to food quality monitoring.

Andy Hannah: The first hurdle was getting the inks to the point where they were good enough for commercialization, and we have accomplished that goal. Companies can now process our inks into a thin film to make an electronic device. We feel the materials are good enough for OLED and OPV applications, but companies need to invest in manufacturing and integrating these materials into the process. There’s been a shift now from R&D to developing ways to process printed electronics devices at a low enough cost.

The second key was to get the major electronics companies interested in the products, especially in OLEDs, and we see Samsung, Sony and LG Ericsson setting up manufacturing. The third key, and what is really new, is that we are seeing end-users wanting to integrate these technologies into their roadmap. We are starting to see customers pull in a big way. We have a lot of end-user companies coming directly to us as an ink supplier, who want to integrate conductive inks into their technology roadmap. We are also starting to see companies like PolyIC and Soligie that can produce components emerge as the bridge between us as an ink supplier to the end product.

Printed Electronics Now: What are the barriers to be overcome to move PE forward?

David Fyfe: Printed OLED displays and lighting are now widely recognized as essential to achieve cost levels that will allow this new technology to displace incumbent technologies such as LCD and plasma in the displays field and fluorescent lighting. The barrier here is confidence that accurate printing on a large scale can be reliable on a 24/7 production basis, and that metrology and repair methods are developed to allow yields in production to quickly achieve break-even levels. In OPVs, the mass manufacturing technology is more or less defined but materials development to increase module efficiencies to 5% and beyond is required. In other applications too, materials development lies at the heart of progress – higher mobility printed transistors with high specification transistor–to-transistor reproduceability, materials which allow in-air printing but most of all educating potential users to the possibilities inherent in PE to solve many of their product problems and open a new era of low-cost, throwaway, devices. We need more companies such as Soligie, capable of integrating a number of PE components on a single web-based substrate for an application.

Andy Hannah: Right now, the key hurdle is getting manufacturing to the point where it can be scaled up at a low cost. Printing technologies need to be stepped up in terms of sophistication.

Printed Electronics Now: Where do you see printed electronics headed in the near term and in the next 10 years?

David Fyfe: I think in the next five years we will see the display and lighting industries adopt printing of their products on a large scale – based on OLED materials technology. I think we will see the medical industry adopt remote monitoring of patients as one of a number of solutions to an aging population putting increasing pressure on bricks and mortar resources such as hospitals and clinics. I think we will see cheap printed sensors applied in many fields using PE. We will see a proliferation of printed displays offering more than just digital numeric information incorporated into patch devices and cards. We will see mass adoption of organic photovoltaic devices made by printing as module efficiencies exceed 5%, in turn driven by materials developments. This in turn will enable a low cost powering of printed devices although printed battery technology will play a significant role too, as will inductive powering of devices.

Andy Hannah: Printed electronics will be integrated into many daily objects., like cell phones and laptop computers. We feel PE will be integrated into our daily lives, whether it will be on store shelves or newspapers with electronic advertising. Twenty years ago, if you asked if people would have thought they would be carrying phones around in their pocket as part of their daily lives, the answer would have been no. That’s how PE will be.