These Are the Materials You Need to Make the Perfect Face Mask, Scientists Say
New research identifies a combination of materials that make the most effective mask.
The coronavirus has made one object a new staple in all of our lives: face masks. And if you're crafty and have managed to secure a sewing machine, you might have considered making a mask yourself. You've likely read a lot about what fabrics you should use, but recent research out of the University of Chicago has identified the perfect combination to make the most effective homemade mask: cotton with chiffon, natural silk, or flannel.
The research team—led by Supratik Guha, professor of Molecular Engineering at the University of Chicago—looked at which household materials best protect users from aerosol particulates. As medical and public health experts learn more about how the coronavirus spreads, one thing has become increasingly clear: Respiratory droplets from coughing, sneezing, and even speaking are the primary means by which the contagion spreads from person to person.
After testing multiple combinations of materials, the University of Chicago researchers found that a layer of tightly woven cotton combined with two layers of polyester-spandex chiffon filtered out the most aerosol particles (80 to 99 percent), which is close to what an N95 mask achieves. Substituting the chiffon with natural silk or flannel—or using a cotton quilt with cotton-polyester batting—produced similar results.
"Cotton, the most widely used material for cloth masks performs better at higher weave densities (i.e., thread count) and can make a significant difference in filtration efficiencies," the study authors wrote in their report, published in the journal ACS Nano. As far as the chiffon and silk, the researchers noted that they have "the combined effect of mechanical and electrostatic-based filtration."
It is worth noting that while a homemade mask comprised of cotton and silk can be effective as an N95 mask, if the end result does not fit properly, and reveals gaps of air around the face, then the efficacy of the mask goes way down. And for more information you need to know about masks, check out 10 Myths About Face Masks You Need to Know.