Montana Tech 3D Printing Masks and Shields


(Story by Kristine DeLeon and photos by Meagan Thompson with The Montana Standard)

Marshall Metcalf in lab at Montana Tech. Photo courtesty of Montana Standard photographer Meaghan ThompsonAn interdisciplinary team of scientists and engineers at Montana Technological University is bringing its tools and various fields of expertise to the effort to get personal protective equipment to clinicians who are treating patients with COVID-19 on the front lines.

As the novel coronavirus continues to spread, demand for face shields, along with N95 masks and other protective equipment, has skyrocketed.

Karen Sullivan, Butte-Silver Bow health officer, said she was worried that “PPE shortages might affect us locally, especially caregivers in long-term care and assisted-living settings.”

Sullivan said she reached out to Tech’s chancellor Les Cook March 19 to inquire about the university’s capabilities for 3D digital printing production after seeing a news story about how Massachusetts General Hospital reached out to Boston-area universities and colleges on their printing production capability.

That’s when Sullivan got in touch with Bev Hartline, Vice Chancellor of Research at Tech, and the project got started.

Sullivan said Hartline got to work immediately.

A group of scientists, engineers, and occupational health experts from various laboratories on Tech’s campus quickly came together in search of solutions.

For the face mask, the Montana Tech Nanotechnology Lab set out to replicate the face masks developed in Boston. They later arrived at a design by a trio of Billings inventors dubbed the Montana Mask, a reusable plastic face mask designed for 3D printers.

“The Montana Mask design worked better than the Boston design,” Hartline said. “But that was put together quickly, so people are still adapting it.”

Hartline said the 3D print masks are not complete yet.

Luke Suttey, Montana Standard photoLuke Suttey, a Ph.D. student in materials science and project coordinator, said they’ve made over 50 masks total but are still in the prototyping phase.

Suttey said the lab has been working with the Occupational Safety and Health Department at Tech to design a mask that would “work on a wide range of people while maintaining fit standards.”

He said the challenge is trying to figure out an easy-to-use design that meets safety standards.

“That’s the goal, and we’re close to that goal,” said Suttey, who works on the modeling and design manipulations of the masks.

He said they’ve been taking each mask design to Lorri Birkenbuel, an assistant professor in safety health and industrial hygiene, to test for fit.

Lorri Birkenbuel, an assistant professor in safety health and industrial hygiene, Montana Standard photoTo do that, Birkenbuel uses an instrument that simultaneously measures the concentration of airborne particles outside versus inside a mask to determine the number of particles getting inside the mask.

This measurement determines whether the mask fits correctly by getting a complete seal.

“We’re taking a lot of filter material and testing each of them using N95 filters as a baseline,” Birkenbuel said.

She said she’s testing different materials on each mask design to see if there is leakage in the different filter materials. A respirator can only work when air passes through the filter. Air will take the path of least resistance, so if the seal isn’t there, the air will go around rather than through the respirator – and therefore lessen the protection.

Birkenbuel said the nanotech lab has given her four designs to test. She said one of the mask prototypes, based on a modified Montana Mask with an added exhalation port, passed the fit test with N95 filter material but not the alternatives.

“The fact that we got it to fit with N95 material is excellent progress,” Birkenbuel said.

Suttey said getting a mask to fit with N95 filter material means that the mask design is good and that they just need to develop a filter that works.

“Basically, if you use an N95 filter, which we know works, and the mask doesn’t fit, then it's the mask’s fault and not the filter’s fault,” Suttey said.

He said they could technically use N95 filters for their 3D-printed masks “but those are hard to get by.”
“This is why testing filters is so important because right now there is a shortage of certified filter materials,” said Suttey, who also works on testing different filtration efficiencies. “If we could find a substitute that is readily available and cost effective then we could produce a lot of respirators to get to a lot of people.”

Suttey said his group’s priority is “refining the design of the mask to pass fit and getting the filter right.”
Meanwhile, Jessica Andriolo, a postdoctoral research associate in biomedical engineering, is working on developing an electrospun filtration media for the face mask using nanofibers.

“Because the fibers are so small, we can actually create tiny little pore sizes,” Andriolo said. “We’re using the same process for making electrospun bandages to create filters...The filter itself is a stretchy bandage material.”

Jack Skinner, an associate professor of mechanical engineering who oversees the nanotechnology lab, said using electrospinning technology allows them to customize filters.

“We’re still developing the filter material that could potentially be sanitized or reused,” Skinner said. He said the plastic masks can be washed and reused, but the filter inserts for now have to be thrown out after each use.

“What’s really cool about what we’re working on is that we could start with nothing but raw material and walk out with masks,” Skinner said. “We can make products that people could use immediately.”
“It really has been a great opportunity to do something useful and good for our community,” Skinner said. “That’s why students go into science and engineering to improve the human condition and solve problems. I’m really proud of the group and how we responded to this need.”

Meanwhile, a small team has been working nonstop to create face shields to protect healthcare workers battling COVID-19.

It’s been an almost nonstop week of production for Bryce Hill, associate professor of electrical engineering at Tech, and graduate student Raven Hrysenko, as they refine iteration after iteration of face-shield designs that will go directly to the Butte-Silver Bow Health Department.

Face shields help protect frontline-workers from potential virus-containing droplets released by coughing, sneezing and other close contact.

Hill and Hrysenko modified an existing design by a Swedish group. Hill said they didn’t like the original design because the shield would pop out from the visor.

They have been relatively easy to make with a piece of clear plastic over the face to protect from splatter procedures, including intubation.

Hill said the group utilizes polylactic acid (PLA), a corn derivative, to 3D print a visor or headband. A shield made of an 8.5x11” transparency film sheet is then attached to the visor.

About nine 3-D printers are crafting their modified face shield design.

According to Hill, the shields they are making are washable and easy to put together. They have been relatively easy to make with a piece of clear plastic over the face to protect from splatter procedures, including intubation.

“Our design doesn’t require two hands to put on or take off,” Hill said. “It’s easy to wash, too, because there’s no elastic involved.”

One average, it takes about an hour to make one face shield, Hrysenko said, and the lab has already produced more than 40 face shields since it kicked off last Thursday.

Hill said the lab is contracted to produce 10 face shields a day for the health department, but the group could make up to 50 a day.

“There’s been a lot of stress in general, but this has been a fulfilling thing for me,” Hill said. “I think the nice part of using a 3D printer is that it doesn’t take a lot of time. Literally, every hour, it just takes 5 minutes to reload and start the printer.”

Hrysenko said this collaborative effort “just shows how a community can come together in a crisis.” She added that it’s fulfilling to do something that makes people safe.