The UK is at the forefront of developing printable electronics.
You wake up and instead of your alarm clock you reach to unroll your paper-thin TV. An enthusiastic broadcaster tells you your schedule for the day, your state of health and the news you want to hear. All of this information can of course be folded away and carried with you to work. You’ll then grab your coat, probably made of self-heating fabric, switch off your illuminating wallpaper and head out the door to face a fully digital world.
While this scenario may appear to be far-fetched, a recent strategy launched by the government aims to develop technologies that will enable products such as these to become reality much sooner than expected. According to business and skills minister Peter Mandelson, the revolution in plastic electronics is set to sweep the world and will fundamentally change the way people interact with each other and their surroundings.
Lord Mandelson is not alone in identifying the opportunities of plastic electronics. Mike Biddle, lead technologist at the Technology Strategy Board (TSB), believes the technology will prove significant in the next 30 years. ‘We are now at the point of turning science fiction into science fact,’ he said. ‘Plastic electronics has the potential to be pervasive in everything we do. Whether that’s through the newspaper that updates, or the near-invisible sensors that monitor our health. If we’re going to develop these products we need to start bringing together the expertise that can make it happen.’
Plastic electronics is a general term used to describe organic materials that are put on flexible substrates, such as paper and fabric, in a similar way to inks used in conventional graphics printing. The deposited materials have electronic functions and can serve as insulators, conductors, light emitters or sensors. The list of potential applications is endless and the industry is expecting massive growth, with top-end forecasts projecting an increase from $2bn (£1.25bn) today to as much as $330bn by 2027.
Heading the plastic electronics campaign, TSB chief executive Iain Gray believes the UK can be at the forefront of this industry and recently launched two multi-million pound competitions to help it happen. ‘With plastic electronics, it isn’t a case of the UK catching up with other countries,’ he explained. ‘We’re actually in the lead and at an exciting juncture of pulling the technology together and coming up with real innovative user applications.’
An area where the UK has shown strength is in the use of organic light emitting diodes (OLEDs). Originally conceived in the late 1980s by researchers at Cambridge University spin-out Cambridge Display Technologies (CDT), OLEDs have been used worldwide in novel display and lighting applications, but so far no one has been able to develop an OLED that matches the performance and reliability of conventional lighting systems.
To address this challenge, a consortium of engineers from Thorn Lighting, CDT and Durham University are working on the TOPLESS (Thin Organic Polymeric Light Emitting Semiconductor Surfaces) project, an effort to create a high-quality white light by applying a single polymeric material to a substrate. This is done in a similar way to rolling paint onto a surface, resulting in a near invisible layer of illuminating light that is one thousandth the width of a red blood cell.
According to Thorn, the technology has the potential to change the way lighting is used and could open up possibilities for products such as wallpaper or clothing that can illuminate without additional internal components. However, the underpinning science is still under debate and while the UK has been focusing on developing polymers and solution-processable molecules, its main competitors, the US and Germany, have been working on an alternative approach using ‘small molecules’. The small-molecule method evaporates material onto a substrate in layers rather than dissolving it in solution, before applying it as a liquid to the surface. Compared with polymer OLEDs, the approach is currently at a more advanced stage and offers a better lighting quality.
However, Geoff Williams, project leader of TOPLESS, claims polymer OLEDs are catching up with their small-molecule counterparts and believes they could open up a niche in which the UK can carve itself a lucrative market. ‘The problem I have with my technology is uniformity and layer thickness,’ he said. ‘The small-molecule guys have the same problem but at a much greater scale. The light-emitting polymer devices are three, maybe four, layers thick, whereas substrates with small molecules have 17 layers. Each layer has to be controlled so you have 17 opportunities for flaws. The UK is making significant progress with polymer OLEDS and we expect the materials will be at least three times better by 2012 than we’re getting now.’
Plastic Logic, another spin-out from Cambridge University, is developing the same polymer electronics technology but for a different application. The company aims to create polymer-based e-readers that present printed text in an electronic form. According to the group, digitisation of text is one of the last remaining obstacles to creating a truly digital world and traditional silicon electronics have so far fallen short of doing this. The main problem with silicon technology is that it uses glass-based displays that require a separate lighting source, which can strain the eyes, reduce battery life and increase the product’s weight. To side-step these issues, Plastic Logic is developing backplane technology that enables a display to become lightweight, flexible and thin. It also recently partnered with Dutch display specialist Liquavista on the £6.1m VideoFLICs project to develop the first generation of full-colour, flexible video-enabled displays.
The company hopes the project will open up a market estimated to be worth around £4bn and lead to the development of products such as electronic newspapers that can show moving images. However, the group faces stiff competition from large corporations such as Hewlett-Packard (HP), which is developing similar ‘information surfaces’ it claims can display paper-like, print-quality information, as well as interactive video and media.
Adrian Geisow, senior research manager at the HP Research and Development labs in Bristol, predicts these products will soon become commonplace. ‘In the same way TV didn’t completely wipe out cinema, I believe the same shift will happen with digital print’, he said. ‘There could always be a place for traditional ink, but we can already see newspapers and magazines suffering. It’s a sign of the times and we’re now ready for something more.’
Geisow added that silicon-based electronics are likely to continue to play a significant role in an industry where more impressive levels of processing power and reliability are in demand. However, this demand will also highlight the design limitations of silicon electronics and, if the, experts are to be believed, it is only a matter of years before plastic electronics are developed to overcome these limitations. The government is optimistic that this will be an arena in which British engineers will help drive forward plastic electronics and make the fully digital world a reality.
The key facts, figures and applications for plastic electronics
- Plastic electronics technology allows circuits to be printed on to any surface and over large areas
- The global market in plastic electronics is forecast to grow from around $2bn to around $330bn by 2027
- The largest growth is predicted in the markets for rollable electronic display screens, ultra-efficient lighting and low-cost, long-life solar cells
- Other applications include flexible batteries and smart textiles
- The Technology Strategy Board has so far invested £52m in collaborative R&D projects in the field
- The government has announced a further £28m of investment to stimulate and grow the plastic electronics sector