Plastic: the way of the electronic future

Plastic electronics have been in the public eye since three scientists won the 2000 Nobel Prize for their contribution to the discovery and development of conductive polymer plastics.

This technology has opened up the possibility of flexible devices - such as information screens that can be rolled up and put in a pocket.

Prof Aimin Song from the School of Electronic and Electrical Engineering is an engineer at the University of Manchester who is pushing boundaries in the field of nanotechnology.

Song has created a way to make single-layered planar plastic transistors and diodes using a fast and simple printing technique.

Song is confident he can push these organic semiconductors to speeds of 100 MHz - far beyond the 20 MHz he has achieved so far.

"Conventional multi-layered transistors/diodes can typically achieve kHz frequencies and under extreme conditions have achieved MHz speeds. But our technology is the only known one that can achieve 800-900 MHz speed for UHV RFIDs using printing technology," Song said.

Plastic components such as semiconductors and diodes could be used to create drivers for flexible displays, RFID devices, smart tags, counterfeit deterrents inside bank notes and passports, disposable sensors/sensor arrays and intelligent disposable sensors.

Song believes that the first application for his technology will be printed smart tags at 13.56 MHz and flexible display drivers for e-paper and that this technology could ultimately lead to the production of information displays that can be rolled up and put into a pocket and also changeable electronic wallpaper.

Other potential applications include intelligent tickets for public transport systems or road toll charging and electronic stamps for letters and packages.

Due to the high level of commercial interest in Song's technology, he has formed a company called Plastic ePrint Ltd with support from the University of Manchester Intellectual Property Ltd.

The firm is now seeking venture capital funding and is also working on creating demonstration versions of plastic RF smart cards and developing plastic components for use in flexible displays.

"The components we have developed are simpler and potentially much cheaper to produce and much faster than previous organic electronic devices," Song said.

"These advantages come from the simplicity of the single-layer, planar structures, rather than the multi-layer vertical structures of conventional semiconductor devices."

Dr Richard Price from UMIP believes that Song's technology has the potential to be at the cornerstone of the plastic electronics revolution: "the nanodevices are so simple, yet extremely elegant".

"Initial applications will have relatively modest functionality compared with today's silicon technology but as materials and processes continue to develop there should be no reason why high-performance products cannot be realised in the future," Price said.

But while the rise of plastic electronics has brought potential, it has also brought some problems. Conventional multi-layered transistors made from polymer plastics offer relatively slow conductivity speeds and involve a complex and costly manufacturing process.

"In the film The Graduate, the character played by Dustin Hoffman is famously advised that the future is plastics. From many points of view, this prediction is quite true and I think that plastics will bring a revolution for the second time in history," Song said.