SEATTLE — Cloth masks may be one of our best lines of defense against the novel coronavirus, but they're far from perfect. Compared to gold-standard N95 respirators, fabric face coverings aren't as good at filtering out the tiniest droplets and aerosols that can carry the pathogen from one person to another.
But a small Seattle startup is hoping to boost the performance of cloth masks with a spray coating that uses minute electrical charges to capture viral particles and prevent them from passing through the fibers.
The approach hasn't been thoroughly vetted and some mask experts are skeptical, but the National Science Foundation (NSF) was intrigued enough to give the company a $256,000 grant for initial development and testing.
"Our goal, for the average person who's using a cotton mask, is to make that mask more effective and to make it safer so they're less likely to contract the virus," said Greg Newbloom, founder and CEO of Membrion, Inc.
Newbloom and his team envision packaging their product in spritz bottles people can use to treat their own masks. The coating would probably need to be replenished daily, at a target cost of $1 per application, he said last week at the Membrion lab in Seattle's Interbay neighborhood.
Until recently, the University of Washington spinoff with a staff of 14 has specialized in flexible, silica gel membranes used in water treatment and purification. Now, about a third of its effort is directed toward face masks.
The firm has yet to turn a profit but has raised $7.5 million in investment funding and $3 million more in research grants. The membranes it produces are electrically charged to help pull pollutants out of industrial wastewater or create fresh water through desalination. The mask project was inspired early in the pandemic when Newbloom's mother asked if the membranes could be used to filter the new coronavirus out of the air.
"I said: 'Of course not, that's not how they work,'" Newbloom recalled.
But then he realized the technology might be applicable to face masks, where the idea of using electrical charges to improve performance has a long history.
One thing that makes N95 masks so effective is an electrostatic charge imparted during manufacturing, said Peter Tsai, the University of Tennessee, Knoxville, materials scientist who invented techniques to both produce the synthetic mesh material and electrify it. The charge makes the filter 10 times better at blocking viruses and other particles thanks to the kind of electrostatic attraction that causes a balloon to stick to your hair, said Tsai, who came out of retirement when the pandemic hit to help develop methods to sterilize N95 masks for reuse in hospitals without degrading the electrostatic charge.