Q&A: Plastic electronics

British firm Plastic Logic has announced that it will build the world's first factory to manufacture plastic electronic circuits.
What are plastic electronics?

Plastic electronics is a branch of electronics that deals with devices made from organic polymers, or conductive plastics, as opposed to silicon.

Organic polymers are a class of substances that are used to make everything from bin bags to solar panels.

The highly conductive polymers needed for electronic devices were first discovered in the early 1960s. They are already used in some electronic devices.

In 2004, electronics giant Philips announced a concept flexible display, while other companies such as Cambridge Display Technology use them to manufacture organic light-emitting diodes (LEDs).

However, plastic electronic devices such as those made by Plastic Logic have never been mass produced.

What will Plastic Logic make at the new plant?

When the production facility is up and running in 2008, it will manufacture large sheets of flexible plastic.

The basic substrate will be polyethylene terephthalate, commonly used to manufacture plastic bottles. Circuits will then be printed on to these sheets.

The plastic chips will then be used as the "control circuits" behind large flexible "electronic paper" displays. These devices, currently being developed and sold by firms such as Panasonic and Sony, can hold the equivalent of thousands of books.

It is hoped that one day these devices will become as common as newspapers and books. The facility will produce one million sheets every year.

How do these differ from traditional electronic devices?

Traditionally, semiconductors have been manufactured from inorganic materials, which do not contain carbon, such as silicon. However, this must be processed at high temperatures in expensive clean room facilities.

In contrast, polymers can be printed using traditional inkjet printers or techniques similar to those used to produce magazines and wallpaper. This means they are cheaper, easier and quicker to produce.

As the polymers can be printed onto flexible substrates they can also be used in totally new types of devices such as electronic paper. Plastic electronics are also more robust than delicate silicon devices.

Will plastic ever replace silicon in microchips?

Not at the moment. High speed computer chips require ultra-pure materials and precision design. The first sheets to roll-off the production line in Dresden will have components 5-10 micrometres (millionths of a metre) small.

By contrast, computer chips routinely use components which are nanometres (billionths of a metre) in size. The relatively large size of the plastic components is a result of the printing techniques used in manufacturing.

However, Plastic Logic say it is currently working on circuits with components 60 nanometres in size. If these are incorporated into working devices it could mean that cheap, flexible electronic chips could be built into items, such as cheap toys, where today current silicon technology is too expensive.

One final obstacle could be performance. Although the plastic devices are suitable for electronic paper displays for example, the speed requirements of modern chips are very different.

But teams are now working on overcoming these limitations. Last year, a US-UK industrial-academic collaboration developed a new polymer six times faster than anything previously produced. However, the material was still "orders of magnitude" away from the speeds necessary for microchips.

Are other companies working on developing plastic chips?

Yes. US firm Lucent, Philips of the Netherlands, Samsung of South Korea and Japan's Hitachi are all interested in