MASK MAVEN. Since mid-March, Peter Tsai, the inventor of the N95
filtration material, has been a worldwide force on two fronts —
finding new ways to sterilize disposable respirators for reuse
and rapidly scaling up their production. (Brianna Paciorka/Knoxville
News Sentinel via AP)
From The Asian Reporter, V30, #08 (July 6, 2020), pages 8
The humble Knoxville scientist who became a
By Vincent Gabrielle
Knoxville News Sentinel
KNOXVILLE, Tenn. (AP) — I started getting calls for help late
in March. Messages came in through e-mail and Twitter from
healthcare workers who were feeling desperate because their
supply of personal protective equipment was dwindling.
"I’ll keep this short and sweet. I’m a nurse and we are
scrambling for PPE," wrote one nurse.
But they weren’t really asking for me. They were asking to be
put in touch with one of my sources, Dr. Peter Tsai of
Knoxville. He responded quickly to these calls for help, even
late at night.
Before the coronavirus pandemic, Tsai was far from a
household name. Even though he was well-respected as a materials
scientist and inventor, very few people had heard of him.
COVID-19 had dragged one of Tsai’s inventions into the
spotlight. He is the creator of the filter material inside most
disposable N95 respirators. As the pandemic worsened, healthcare
workers nationwide needed the masks to stay safe, which means
there were shortages and massive price markups.
The shortage was so dire that it brought Tsai out of
retirement to dive head-first into solving the crisis.
Since mid-March, Tsai has been a worldwide force on two
fronts — finding new ways to sterilize disposable respirators
for reuse and rapidly scaling up their production.
"My invention is just an ordinary invention," the 68-year-old
said humbly in an interview with Knox News. "But because of the
need for the respirators, people think it is very important."
Tsai’s invention is not new. He filed the first patent for
the filtration technology back in 1995. His invention gives the
masks’ filter fabric a permanent electrostatic charge by
exposing it to a halo of electricity. Scientists call this an
electrical "corona." Tsai named his process "coronal charging."
The coincidence between the names is not lost on Tsai.
"I use coronal charging to fight coronavirus," he joked.
Tsai has had a long career in textile manufacturing and
engineering. He graduated in 1975 from what is now National
Taipei University of Technology. He worked for several years in
manufacturing before moving to the U.S. in the 1980s to obtain a
doctorate in materials science at the University of Kansas.
During his research career at the University of Tennessee
Knoxville, Tsai developed his filtration technology further
while pursuing other projects. He holds 12 U.S. patents in
filtration technology and other areas.
While his material and production processes made a huge
difference in the world, it wasn’t front-page news. He retired
in late 2019. Then you know what happened this year.
"I felt very stressed in the very beginning," he said. "I got
a lot of pressure and a lot of questions."
He knew the kinds of stress the respirators could tolerate,
and he published these thoughts in the Journal of Emergency
Medicine in a special emergency article. He turned his home
into a lab and published more results.
One group donated an ozone machine commonly used in hospital
sterilization to see if that would work. Tsai boiled and steamed
masks. He borrowed a neighbor’s oven to see if masks could be
safely heated using common kitchen appliances. He exposed
respirators to sunlight. The masks were then tested again to see
if they lost filtration power.
Ozone was a no-go because it ruined elastic or rubber ear
loops. Wet heat had to be applied carefully to avoid deforming
the masks. Home ovens heated too unevenly and inaccurately.
Alcohol ruined the filters. Other techniques, like dry heat and
hydrogen peroxide, seemed more promising.
But Tsai couldn’t fully test every technique, nor could he
validate that it killed viruses. This worried him.
"I started wondering whether people were using my methods
without validation," Tsai said. "If it does not really sterilize
the mask and people reuse them, then we would have a lot of
He reached out to other scientists and got in touch with a
team at the University of Tennessee Medical Center to validate
his approaches. N95DECON, an inter-disciplinary research group,
also got in touch. It ran its own tests to validate some of his
suggestions in addition to others.
N95DECON recommends versions of some of Tsai’s initial
approaches for sterilization. Its validation studies cite
communications with Tsai and the experiments of over a hundred
N95DECON members. Their results echo some Centers for Disease
Control and Prevention suggestions for mask sterilization.
But reusing masks is only half the battle.
The world faces a critical supply shortage. Few domestic
suppliers make N95 filtration material. Half the world’s N95
masks are manufactured in China. The Food and Drug
Administration recently deauthorized many models of N95 masks
from being reused.
Unbeknownst to Tsai, Oak Ridge National Lab (ORNL) was
gearing up to try to address the problem.
"We have a lab-wide initiative effort on COVID-19," said Dr.
Merlin Theodore, director of the Carbon Fiber Technology
Facility at ORNL. She explained that the facility was struggling
to come up with a way to convert its machines to make the filter
fabric and was looking to enlist local experts.
Dr. Lonnie Love, a lead scientist in ORNL’s COVID
manufacturing task force, remembered Tsai but couldn’t put his
finger on why.
"He remembered the name and couldn’t remember why so he asked
his wife," Theodore said. As it turns out, Tsai was neighbors
with Love’s mother-in-law. After that, they quickly made
"He came that very same week, fully suited up. He brought his
own equipment," Theodore said. "He reminded me of someone going
With Tsai’s expertise, the team at ORNL was able to quickly
convert its carbon fiber processing facility into a filtration
cloth facility. Within a week it was able to produce filter
cloth. Theodore says it’s impossible to say how much time Tsai’s
"Just imagine the amount of experiments you’d have to run to
determine a process that works," Theodore said. "That can
average from months to years. But we didn’t have to because he
had already done all the experiments."
The ORNL facility can produce enough material for roughly
9,000 masks per hour. It’s shipping the material to academic and
national labs for research purposes. Theodore explained that for
the market, ORNL worked with industry partners to get the fiber
technology into domestic manufacturers’ hands quickly.
A spokesperson for ORNL confirmed that it had assisted a
filtration material manufacturer based out of Cookeville,
Cummins, with the installation of equipment to produce Tsai’s
Tsai said this was far from the only consulting work he had
been doing. He said he’d been doing pro-bono consulting work and
research around the clock.
Theodore said Tsai vigorously tried to turn down payment for
his work with ORNL but had to be paid per ORNL policy. Tsai said
that being helpful during this time was all that mattered to
"This is an opportunity for me to contribute to the
community," he said. "If I can do this, it will be a good memory
for the rest of my life."
The work has not been without its toll. Tsai said that since
the start of the pandemic, he had lost 10 pounds, but he was
"Someone said I should get a Nobel Prize," Tsai joked. "But
what I deserve is a ‘No Belly’ prize."