HALIFAX, N.S. — Give a group of engineers some 3D printers and a Staples gift card, and it’s amazing what they can come up with.

An “engineering task force” at Dalhousie University, working with the Nova Scotia Health Authority, took seriously a call from the federal government to use their expertise to take on COVID-19.

What they came up with, using 3D printing technology, is a way to reduce the shortage of face shields needed by health-care workers.

“Originally we were talking about ventilators, but ventilators are really complicated, really delicate things,” said Clifton Johnston, who is leading the Dal team and is an associate professor of mechanical engineering.

Johnston and several of his colleagues took 3D printers home with them. He said his is the size of “two microwave ovens stacked on top of each other.”

“When there was the idea that we might be able to help by 3D printing, we were looking at how to manage it, given that Dal was working at a distance and they didn’t want people in labs,” Johnston said. “A lot of other people, like NSCC and NSCAD and companies have gotten in touch and said, 'Hey, we’ve got 3D printers and we’re happy to help, let us know what we can do.'”

“The ones I have at home are about $1,300 and they’re quite good quality. We have other ones that are worth $50,000 and we have ones that are worth $5,000. We’re not taking those home.”

One of the prototype headbands for face shields being created by Clifton Johnston. The Dalhousie professor and students are 3D printing face shields to help bridge a possible shortage if the Nova Scotia Health Authority needs them. - Eric Wynne

Johnston was sent an article about a university in Hong Kong working to make face shields, and he shared that idea with his group of eight to 10 people.

“The face shield has three parts, the clear shield cover which is not printable, the headband the clear plastic shield attaches to, and there’s an elastic that holds the headband onto your head. We 3D print the headband part, which takes about an hour and a half to print,” he said. “The 3D printers we have use a roll of plastic filament. Imagine a spool of 1.75-millimetre plastic thread. You feed it into this machine that has a brass nozzle that gets heated up…so basically it keeps pulling more plastic in, melts it in the nozzle and pushes it out on to this controlled platform that moves.”

The plastic filament costs just $20 a kilo, and Johnston’s team has the capacity to make about 1,000 headbands a week.

Unfortunately, that’s not enough, so work has shifted to making the headbands by the use of injection moulding, a faster process. Johnston has found a company that says, given a design, they could produce 10,000 headbands a week.

No matter how the headbands are made, they’re no good to doctors, nurses or respiratory therapists without the actual face shield.

This is where Johnston’s team showed why only smart folks get engineering degrees.

“You know what works pretty good for this? Clear plastic report covers, like the ones that go on your spiral bound report,” he said. “You can get them at Staples, they’re quite cheap and they could just buy them and ship directly to NSHA in large quantities. Then the headband would be designed to match up with a standard three-hole punch and punch three holes in that plastic piece, which would then fit onto little pins on the front of the face shield.”

One of the prototype headbands for face shields. - Eric Wynne

Team member Craig Arthur said several people were working on the headband design simultaneously, though never in the same room at the same time.

“It definitely has been a steep learning curve for everyone to incorporate technology fully. The biggest difference for us is you can’t get the key designers in one room around one table, picking up prototype and talking about it,” said Arthur, also part of the Dal faculty of engineering. “People would say ‘Hey, I found this feature from this design,’ and when we found something we really liked, that got incorporated into the prototype that we were working on.”

While his colleagues are working from home, engineering professor Jeremy Brown still goes to work every day in Dalhousie’s fabrication lab, having received special permission to do so.

“If you’re working on COVID-19 research, you can get permission to come in and use your lab under certain circumstances,” said Brown, who didn’t know about the personal protective equipment shortages until he was asked to work on the task force.

“I immediately started Googling what other people were doing around the world, and sent a link to one of my graduate students, and he just started remotely printing one of these prototypes. Within two hours, we had a prototype in the room,” Brown said, who is now working on some small tweaks to the headband design before manufacturing by injection moulding begins.

He described the process of virtual meetings as “surprisingly seamless.”

“Makes me wonder why we ever had in-person meetings.”

