Prints perfect

The UK’s fast-growing inkjet printing industry will get the support of its own multi-million pound R&D centre, due to open early next year.

Cambridge University, backed by a nine-company consortium, will use a 2m EPSRC grant to develop advanced inkjet technology, widely viewed as the key component in the next generation of large-scale, high-resolution graphics printing.

Inkjet printing also has a host of potential applications across manufacturing sectors, where it could be used to mass-produce electronics systems such as circuit boards, RFID tags and polymer LEDs. The accuracy of the technology needs to be improved if it is to fulfil this potential.

Inkjet printing directs fluids at high speed through anozzle on to a surface, either in a continuous stream re-directed by an electrostatic field – traditionally used to print low-resolution images such as yoghurt sell-by dates – or through more advanced ‘drop-on-demand’ techniques, in which a digitally-controlled nozzle can greatly improve image quality.

Prof Ian Hutchings of Cambridge’s department of engineering claimed that the research will lead to a better understanding of fluid behaviour and nozzle design, enabling advances in printingquality and reliability.

‘Inkjet printing uses highly complex, multi-component fluids, which go through a very fine nozzle at extraordinarily high speeds; the shear rates involved are exceptionally high and quite outside normal fluid rheology measurements,’ he said. ‘With a more robust model, we should be able to use a much more quantitative approach to designing fluids and nozzles.’

A number of initial technology performance targets have been set, including drop-on-demand accuracy down to two microns in a single pass and elimination of unwanted ‘satellite’ droplets that degrade print quality.

Nine companies in Cambridge’s well-established inkjet technology community have contributed a total of 1.1m in addition to the EPSRC grant.

Organisations involved include Xaar, which produces advanced printheads, and Fuji Film Electronic Imaging, as well as CambridgeDisplay Technology and Plastic Logic, which plan to use the research to develop polymer-based electronics.

Hutchings said there was an urgent requirement for industry to work together to maintain the UK’s head-start in the technology. ‘The benefits for industry are greatly reduced lead times, reduced costs, increased performance and reliability of their systems. We hope to develop a UK centre of expertise that will thrive beyond the initial funding,’ he said.

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