Using knowledge gleaned from nuclear weapons work Sandia National Laboratories has developed a new way to make and test high-quality N-95 face masks
National Nuclear Security Administration
October 16, 2020
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Using techniques honed from nuclear weapons testing and quality assurance, Sandia researchers have developed a novel method to generate and test high-quality N-95 face masks to protect front-line medical professionals. Just as importantly, Sandians are working with small businesses in New Mexico to test the new respirator materials.
A media comprised of a sandwich of materials, tested by Sandia, is being manufactured into N95-like respirators that could be used in local medical facilities. The project originated from the urgent need for personal protective equipment when the COVID-19 outbreak began.
“I can almost assure you that no one else in the country is making respirators the way we’re making them,” said Dave Mayberry, technical lead for Marpac, Sierra Peaks and Sew-EZ, the companies that worked with Sandia on materials testing.
“We didn’t want to research the same materials already used in the typical N95 supply chain due to availability issues, so we looked into other materials we could get ahold of that seemed most likely to meet the filtration requirements.”
Sandia’s material testing capabilities has its roots in weapon quality assurance, a field of expertise which allows NNSA to support a defensible reliability assessment of weapons in the stockpile. Stockpile testing consists of conducting the same kinds of tests as in new material testing.
Marpac, Sierra Peaks and Sew-EZ were matched with Sandia scientists through the New Mexico Small Business Assistance program that pairs Sandia and Los Alamos national laboratories with companies seeking help to solve technical problems.
“It’s been very satisfying to see NMSBA, a state program, help New Mexico businesses address COVID-19 issues,” said Jackie Kerby Moore, former manager of technology and economic development at Sandia. “It was also rewarding to see the Sandia team jump on the opportunity to help these three businesses with their respirators.”
We didn’t want to research the same materials already used in the typical N95 supply chain due to availability issues, so we looked into other materials we could get ahold of that seemed most likely to meet the filtration requirements.
Marpac specializes in manufacturing medical tube devices and works closely with engineering and manufacturing companies Sierra Peaks and Sew-EZ.
Mayberry reached out to Sandia after receiving an inquiry from a local hospital to see if the company could help address the potential shortage of N95 respirators. Certified N95 respirators are worn like masks and protect users from 95% of airborne particles and liquid contamination.
Sandia has the equipment and expertise to help, and within a few days after Marpac reached out, a team of scientists began working on the challenging task of modifying systems to make sure samples were tested properly. Sandia principal investigator Michael Omana said the team modified aerosol and filtration systems typically used for nuclear nonproliferation work. They had to reduce the systems’ airflow significantly to mimic the rate that humans breathe.
Initial test materials underperformed, but within a couple of weeks, the researchers started seeing promising results from new material compositions. Creativity in combining materials resulted in protection levels comparable to N95 respirators.
Marpac manufactured 500 N95-like respirators using the materials Sandia tested, and Mayberry said they passed fit tests at a local hospital. They’re also looking into additional medical facilities that could use the product.
“This definitely stretched us out of our comfort zone, and certainly without the technical support from Sandia Labs, this would have been hard to validate all the types of materials that would be likely constructed into a respirator,” Mayberry said.
Working quickly was critical for the projects, Sandia distinguished technologist Dora Wiemann said, and the team put in long hours — including on weekends.
The projects with each company built upon each other. For the first project with Marpac, researchers tested sheets of composite materials provided by the company in the large, modified filtration system.
For the second project with Sierra Peaks, additional test-box modifications enabled the scientists to mount and seal samples cut in respirator geometries, and to complete comparison studies against certified N95 respirators.
The third project with Sew-EZ, involved further sample testing using the filtration system and an additional commercial-off-the-shelf system, which is typically used by industry to certify products like N95 respirators.
Omana and a couple of other researchers test the materials in the lab, then forward data to be processed into quantitative results. The timeline on all projects has been tight, but the researchers said promising tests have been rewarding, especially because the result has the potential to help people during a time of crisis.
“Sandia is not a certification lab, but the joint use of the systems enabled us to provide data that may be compared against products which have been certified through traditional avenues,” Omana said. “This data will help the company if it chooses to seek certification of its product through the proper organizations.”