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Flexible and Printed Electronics:
Transformational Technology for Life Systems
Flexible and printed electronics describes a broad set of technologies applicable across a multitude of products. These may be very small, such has cell phone components, or very large (literally thousands of square meters), enabling applications that can only be dreamed of today. Flexible and printed electronics enables the production of devices that can be readily integrated into all aspects of life in a seamless manner, at low cost, on large scales, using inherently “green” processes and materials.
 These elements - flexible and printed electronics – each describe a different aspect of improvement over traditional silicon electronics :
Flexible is an attribute of the devices or components – unlike silicon microelectronics, they can be bent or shaped without being damaged. This allows integration into everyday items and places, such as textiles, medical bandages, and lighting fixtures.
 Printed refers to the manufacturing innovations that make it possible to make products at low cost, using green materials and on flexible substrates. Devices can be printed with nearly any method used by the graphic arts industry today, including offset, gravure, flexo and ink jet printing.
Flexible, printed electronics is inherently “green technology” and, in many cases, replaces the materials in traditional electronics, including toxic elements such as antimony, with plastics and inks. These new materials have the advantages of low energy consumption, high fault-tolerance, transparency, light weight and shock resistance.
Notable attributes of flexible, printed electronics are:
- Lower materials and manufacturing costs
- Enabling novel applications not practical to manufacture today
- Transformation of U.S. print manufacturing capacity for electronics manufacturing
Markets and Product Opportunities
Flexible and printed electronics will change the way we work, live and think, and have dramatic impact on the markets for digital displays, lighting, energy harvesting and storage, and healthcare. Unlike traditional electronics, flexible and printed electronics can be shaped, bent or rolled, and produced via roll-to-roll manufacturing processes. It is the only way to enable volume production of some clean technologies, such as solid state lighting and photovoltaics. Products made possible by flexible and printed electronics in displays, lighting, sensors and solar have been invented, but are not on the market in any volume because the volume manufacturing infrastructure is not yet in place.
 Flexible solar panels. Traditional photovoltaic solar is made from a silicon wafer encased in glass, and are expensive, heavy and easy to break. With the support of the Department of Energy (DOE), pioneering U.S. entrepreneurs are now inventing lightweight, flexible solar cells. The U.S. leads the world in this flexible solar technology and could easily become a leading producer with proper investment.
 Printed Lighting. Organic Light Emitting Diodes (OLEDs) are a printed electronics lighting technology that can be 100% efficient – pure light with no wasted energy creating heat. Low-cost OLED lighting installed as wallpaper and ultra-high contrast, flexible displays are among the applications being developed with this technology. Investments in new materials and the manufacturing infrastructure are needed.
 Medical devices. Flexible and printed electronics could enable medical innovations that will dramatically lower healthcare costs while improving the overall quality of care. For example, making possible flexible electronic bandages that monitor health, dispense prophylactics, and warn when you need more serious treatment, all without the need for human intervention. Newer flexible materials will make implanted artificial eyes and brain-linked artificial limbs possible for the first time.
Emerging opportunities. Flexible and printed electronics will also enable capabilities that can only be dreamed of today, such as intelligent clothing, structure-integrated sensors, wearable medical diagnostic tools, and implantable RF devices.
Worldwide Interest
Over the past few years, a number of academic and industry workshops have been held as this field has started to take shape. A 2003 National Academy of Sciences Report entitled “Materials Science and Technology: Challenges for the Chemical Sciences in the 21st Century” stated in the executive summary, “In the future, structural materials will incorporate sensing, reporting, and even healing functions into the body of the material.” In 2006, iNEMI created a first technology roadmap for organic and printed electronics, stating, “This seemingly unlikely marriage of the microelectronics and the graphic print industries shows incredible promise to spawn an entirely new method of electronics manufacture for large consumer electronic product markets.”
Worldwide investment in flexible and printed electronics is rapidly growing. The European Union has granted or committed more than $700M in R&D funding between 2001 and 2013. In 2005, the German government announced a 5-year program funded with an investment of up to $140M. Among the Asian “Tiger Economies”, Taiwan’s Science and Technology Advisory Group has announced a $120M initiative to establish at least 15 companies specializing in flexible electronics with the goal of capturing 20% market share by 2015.
Challenges for Success
In 2007, the U.S. Display Consortium (USDC) organized a National Working Group on Flexible Electronics and convened three workshops on flexible and printed electronics to further identify current status, critical needs and opportunities. The USDC Working Group identified the following sets of critical needs:
Improved Materials Performance – Organic materials show some electronics properties that approach those of common conducting and semiconducting materials used in microelectronics. The identification of new materials and their properties has closed this gap significantly in the past few years and there is reason to believe that this improvement will continue with further research. There have also been significant advances in inorganic oxides and nanomaterials. Needed are improvements in breakdown voltage, mobility, and leakage current for these materials that will enable faster transistors, better solar cells and sensors, and more efficient lighting, for example.
Material Stability and Improvement – Many of the more promising materials show some degradation, due to the environment they are used in or under prolonged use. Needed is an understanding of the fundamental degradation mechanisms to determine how to improve these materials and to develop barriers, sealers and encapsulants that make them suitable for long-lived applications. Materials used in a medical environment may only need to have a short lifetime, but those used in building materials or remote sensing applications could require usage measured in decades.
Patterning Technology – Improvements in throughput, resolution, and registration capability are essential for increasing the capability of printed electronics. Much like Moore’s law for semiconductors, we can expect the pace of change to be dramatic, allowing ever increasing complexity for printed electronic systems as the technology advances. Development of flexible tools capable of combining printing approaches would be beneficial, as would in-line characterization tools that can drive rapid manufacturing and yield improvement.
Design Tools – An essential ingredient to the rapid customization of electronics today is the ability to simulate new circuits and verify that they will meet the requirements even before production is started. Needed are similar tools for the printed electronics industry that can enable designers to predict performance, and design components and circuitry with these new materials.
Integration – Hybrid devices that combine the benefits of conventional silicon circuitry with large area flexible electronics will enable many new systems and capabilities. An understanding of how to best optimize this system approach, how to interface between printed and conventional electronic components and how this evolves as printed materials improve are needed.
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