If the scientists, designers, and engineers behind printable, flexible, and wearable electronics want to move their industry forward, they need to approach the development process in an interconnected way or risk irrelevance, one of the field’s most distinguished leaders told a room full of industry colleagues this week.
“Whether you’re talking about the tools, the materials, the processes, or the systems, I truly believe that you have to treat every part of it as an interconnected piece.” Vivek Subramanian, a professor from the electrical engineering and sciences department at the University of California Berkeley, said. “If you just say, ‘here’s this inkjet printer that people have been using to create graphic arts forever and I’m going to stick some electronic ink into it and print electronics,’ it’s never going to work.
“Every stage of the process needs science and engineering,” he continued. “And if you do that, then you can really push the technology.”
Subramanian was in the Toronto area on April 20 to give a keynote address at the Canadian Printable, Flexible and Wearable Electronics Symposium (CPES2016), where he walked the audience through every stage of the development process, using his own team’s work on gravure printing, transistors, and microelectric mechanical systems as examples.
For example, the gravure printing process, which uses a hard cylinder filled with ink to roll a design onto a surface before wiping the cylinder with a “doctor blade” meant to keep the wells filled while removing excess ink, actually leaves a “tail” created by ink wiping the back of the doctor blade, Subramanian explained. To correct this, his team calculated an ideal speed for the gravure – fast enough that it doesn’t create a tail, but not so quickly that the ink isn’t given a chance to dry, creating a layer of lubrication.
He showed that electronically printed transistors, which should have a narrow, uniform gap between two conductors, have a bulge at one end where the ink collects if printed in a straight line. His team ultimately solved the problem by printing the conductors in an “L” shape, which allows the ink to collect on two ends where it could be cut off.
As for microelectric mechanical systems, Subramanian said that his team ultimately designed 3D-printed materials that could be used in place of semiconductors.
“As an academic group, it’s relatively easy for us to be vertically integrated,” he admitted. “We can take on all aspects of the process. Realistically if you look at the industry it’s a harder to do because they need to be more focused and work towards a product.”
There are two ways to solve this problem, Subramanian said. One is to set up a consortium that includes toolmakers, material suppliers, and developers, similar to the Canadian Printable Electronics Industry Association (CPEIA), the organizers behind CPES. The other, particularly in research, is to maintain a careful approach to new applications, paying equal attention to the latest breakthroughs and their underlying technology.
“The application should not be the sole thing you worry about,” he said. “You have to develop everything else under it.”
“If all you’re doing is gee-whiz demos of, ‘look, I can do this! I can do that!’ the technology never develops under it,” he added.
ITBusiness.ca is a media sponsor of CPES, which was held this year on April 19 and 20 at the Oakville, Ontario campus of Sheridan College.
