One Cal Poly engineering student’s 3D printing hobby turned into a way to combat medical equipment shortages after he was approached to print N95-style respirators out of his garage.
Jeremy Ralston, a facilities engineer at the San Luis Obispo Surgery Center, saw a need for higher N95 respirator production in the midst of the pandemic. He reached out to Cal Poly’s amateur radio club seeking someone who could 3D print the masks. Ralston was then directed to materials engineering and manufacturing engineering senior Cristian Sion.
Sion’s garage has housed up to five 3D printers for around two and a half years, mostly being used for class projects and his 3D printing service, Additive Engineering. He had not worked on N95 respirators until Ralston approached him about the project at 12 p.m. on Mar. 23.
Accepting the offer to help immediately, Sion made three masks to present to Ralston by 8 p.m. the same day.
“This was the perfect opportunity for two reasons,” Sion said. “One, I was helping the community. Two, I love 3D printing.”

N95 respirators are the personal protective devices being utilized by healthcare professionals and first responders during the COVID-19 pandemic, as they can block at least 95 percent of airborne particles from entering the respiratory system.
Although healthcare facilities use these masks regularly, production of the devices is allocated based upon previous usage rates. According to the U.S. Food and Drug Administration, the unprecedented spike in use of N95 masks this year, as well as the unnecessary use of them by the general public, is causing a shortage for many healthcare organizations.
Before mass producing the respirators, Sion and Ralston teamed up with Dr. Clint Slaughter, an emergency room physician at both French Hospital Medical Center and Arroyo Grande Community Hospital, to improve the popular N95 “Montana Mask” design.
“[We] ended up going over to French Hospital, helping them test [our mask] and then listening to feedback and then updating the design,” Sion said. “The best improvement we made was that we increased the filter surface area by 50 percent.”
Since making improvements, Sion and his team have now made over 200 N95 respirators, each of which take about five to six hours to print. While the production time could be shortened, Sion explained that doing so would lessen mask quality.
According to Slaughter, local hospitals currently have “adequate” equipment for the next couple of months, but access to locally produced supplies will be helpful in the case of patient increase.
While the goal for Sion and his team is to get these masks to health professionals who are especially vulnerable to the virus that has resulted in over 23,000 U.S. deaths, 3D printed masks are not approved by the FDA or National Institute for Occupational Safety and Health (NIOSH) as true N95 products.
Sion and his team have been contacted by two hospitals in Los Angeles to test the design of the mask, which is currently an open source document. They have also sent masks to a community service organization where they give showers to the homeless in Santa Barbara.
Until approved, the trio is continuing to work on the respirators and said that although this grade of mask is not necessary for anyone other than healthcare professionals, they can be used by the general public.