Researchers at Northwestern University have designed a face mask with the ability to sanitize exhaled respiratory droplets, making the wearer less infectious and protecting others.
Respiratory droplets produced during coughing, sneezing, or talking can cause the transmission of respiratory viruses such as SARS-CoV-2. These droplets can reach a distance of over 4 to 6 meters and can remain suspended in the air for an extended period of time. Therefore, public health officials highly recommend the use of face masks to control the spread of COVID-19.
While some individuals, for reasons completely unknown, may disagree, the majority believe in the potential of face masks. Furthermore, research has shown that face covering, including homemade face masks, significantly reduces the risk of cross-infection.
Face Mask Sanitizes Exhaled Respiratory Droplets
Masks are perhaps the most important component of the personal protective equipment (PPE) needed to fight a pandemic. We quickly realized that a mask not only protects the person wearing it, but much more importantly, it protects others from being exposed to the droplets (and germs) released by the wearer.
Jiaxing Huang, lead researcher
Masks generally block the respiratory droplets, but some may escape and infect others directly or indirectly. Hence, researchers at Northwestern University set out to design a face mask that would make the wearer less infectious. They aimed to chemically modify the exhaled respiratory droplets as they escape the masking layer thus, inactivating the virus.
Huang and his team looked for breathable mask fabrics that could easily load the antiviral chemicals. They tested the chemical modulation on a medical gauze and lint-free wipes. Next, they coated the fabrics with a layer of polyaniline, a conducting polymer. This allowed the antiviral chemicals to load onto the mask fibers.
The researchers chose Phosphoric Acid and Copper salts for antiviral agents because they are nonvolatile. Therefore, not a potential inhalation hazard. Furthermore, both these chemicals can easily dissolve in exhaled droplets.
Public Health Equipment
The team published their findings in the journal Matter. They found that even low-density fibers such as medical gauze, altered 28% of the exhaled respiratory droplets. Whereas, the lint-free wipes sanitized up to 82% of the droplets.
The work is done nearly entirely in lab during campus shutdown. We hope to show researchers in non-biological side of science and engineering and those without many resources or connections that they can also contribute their energy and talent.
Jiaxing Huang, lead researcher
The research highlights the importance of wearing face masks during a pandemic. The on-mask chemical modulation suggested by the researchers can play a key role in protecting healthy individuals from asymptomatic COVID-19 patients. Moreover, it may also help protect frontline workers
Reference:
Huang et al., On-Mask Chemical Modulation of Respiratory Droplets, Matter (2020), https://doi.org/10.1016/ j.matt.2020.10.012
Verma, Siddhartha, et al. “Visualizing the Effectiveness of Face Masks in Obstructing Respiratory Jets.” Physics of Fluids, vol. 32, no. 6, 2020, p. 061708., doi:10.1063/5.0016018.
