Researchers have filled an off-the-shelf inkjet printer with semi-conducting polymer "ink" to print computer displays and solar cells on to a multitude of different surfaces.

Ghassan Jabbour and Yuka Yoshioka at the University of Arizona, Tuscon, replaced the ink found in ink jet printer cartridges with different organic liquids used to form semi-conducting polymers.

The printer used can control the amount of ink dispensed on a surface to within a few picolitres and about 25 microns. Adapting the printer software makes it possible to create precise circuits with a number of different types of semi-conducting polymer.

Each polymer has a different conductivity, Jabbour told New Scientist.

Textiles and glass

The researchers have so far used the technique to make simple organic LED arrays that display images when connected to a power supply, as well as power-generating solar cells. But Jabbour believes the technique could be used to create many different types of device.

This flexibility comes in part from the ability to print semi-conducting polymers on many different surfaces, he says: "We have put them on to textiles, silicon wafers, plastic, glass - you name it."

Because the polymers are transparent, solar or LED arrays could be painted invisibly on to glass. The researchers say it is also possible to design cells that emit or are sensitive to infra-red light. Jabbour estimates it will take five years for the technology to be developed commercially.

Others are investigating similar technology. For example, Plastic Logic, a Cambridge University spin-off company, has developed a customised inkjet printing technique to create organic polymer circuits.