COVID-19 prompts a team of engineers to rethink the humble face mask
John Xu is a research scientist in the lab of mechanical
engineer Friedrich
“Fritz” Prinz, where the two are known for their work on creating fuel
cells for next-generation cars.
Xu, who received his PhD in
Mechanical Engineering in 2016, spoke to us about their work. Excerpts follow:
What
problem did you set out to solve?
We’ve all become familiar with the
value of surgical face masks in both preventing infection or, in the case of an
already infected person, in preventing further spread of the disease. The masks
essentially filter the air coming in and out of the lungs, trapping the virus
and other particles in its mesh. Through the COVID-19 crisis, many have become
familiar with N95 masks, which filter out 95 percent or more of small
particulate matter from the air — including the virus.
But in filtering those particles,
the mask also makes it harder to breathe. N95 masks are estimated to reduce
oxygen intake by anywhere from 5 to 20 percent. That’s significant, even for a
healthy person. It can cause dizziness and light-headedness. If you wear a mask
long enough, it can damage the lungs. For a patient in respiratory distress, it
can even be life threatening.
How
have you tried to address that problem?
The Prinz Laboratory team was
already working on electrochemical conversion of oxygen from the air for energy
applications for sustainable automobiles. It’s important to remember that
ambient air is only about 21 percent oxygen, so we wanted to see if we could
extract more oxygen to provide a more-concentrated flow — we call it oxygen
enrichment. It’s a common process in combustion and electrochemical fuel
conversion because you need oxygen to burn things. Our goal was to develop a
portable device that uses these electrochemical processes to enrich oxygen from
the ambient air.
We are working on a couple of ways
to do this. The first is a classical process known as splitting water. If you
collect water and run an electrical current through it, the additional
electrons will cause the water to split into pure hydrogen and pure oxygen. The
hydrogen can be used as a fuel and the oxygen goes to the mask to be breathed.
The other reaction we’re working on involves moving oxygen-containing anions —
a negatively charged atom or atoms — through a membrane to isolates the oxygen
on one side where it can be collected and directed to the mask.
Do
you have a working prototype?
We do. It is a small box that is
worn at the waist with a tube that extends to the face mask.
The device we have created actually
generates clean, pure oxygen using this electrochemical process to
supplement loss of oxygen due to masking. We think it can protect the
respiratory system of long-term mask wearers, particularly healthcare workers
and patients.
Who
is the primary target for this device?
We are targeting this to anyone who
has to wear a mask for the long term, first responders, doctors, nurse and even
patients who don’t want to infect others. In the near term, we hope to get
these into healthcare workers as soon as possible. We are working with Allison Okamura and
her postdoc Ming Luo to make it a wearable pneumatic device with additional
engineering physics and user-experience design modifications.
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