Not so long ago, the idea of printing an electronic circuit would have sounded highly futuristic and sci-fi. But the future, say printed electronics experts, is now here. One exciting recent example hails from North Yorkshire’s The Ryedale Group, which won this month’s inaugural Stationers’ Company Innovation Excellence Awards.
What did the job entail?
Ryedale’s winning entry was a low-cost gas sensor, designed to pick up chemicals in a person’s breath that might indicate that they are suffering from cancer or diabetes, for example. The company has initially targeted healthcare applications, but said the technology would be suited to a wide range of purposes. “It could be used by drinks brands to check their suppliers are supplying the correct product, for instance. Or it could be used on the shelves of supermarkets to show when food is starting to go off,” said Ryedale group director of operations Steve Buffoni.
How was it produced?
The sensors are produced by litho printing conductive inks onto plastic. Ryedale has experimented with polystyrene, polypropylene, and polyester for the substrate, as well as standard board, and is developing its own carbon-based inks that are “much cheaper than the alternative silver and gold inks,” according to Buffoni. A polymeric coating is added to each sensor, with the type of coating depending on the chemical being detected. When a gas is passed across the sensor, it attracts the relevant VOCs, sending data to a connected computer.
What challenges were overcome?
Getting the conductivity just right was key, said Buffoni. “UV litho only puts down a very thin layer of ink, but a thicker layer is better for conductivity. So the challenge was getting a thick enough layer,” he said. “It has been more difficult to achieve the conductivity on plastic substrates, but you end up with a far more robust product in the end.”
What was the feedback?
Stationers awards organiser Tony Mash commented: “The judges believe that Ryedale’s invention has the potential to be genuinely game-changing in print, electronics and manufacturing. It was deemed to be an innovation at the frontier of print technology and with a clear business delivery plan.” Ryedale is now in talks with potential customers for the sensor.