MIT scientists design face mask that can inactivate coronavirus

Washington: Scientists at MIT have designed a novel face mask that can not only filter out the SARS-CoV-2 virus, which causes COVID-19, but also inactivate it using heat.

The new mask incorporates a heated copper mesh and does not need to be decontaminated or thrown away after use, according to the researchers.

As the person wearing the mask breathes in and out, air flows repeatedly across the mesh, and any viral particles in the air are slowed and inactivated by the mesh and high temperatures, the researchers said.

Such a mask could be useful for healthcare professionals, as well as members of the public in situations where social distancing would be difficult to achieve, such as a crowded bus, they said.

"This is a completely new mask concept in that it doesn't primarily block the virus. It actually lets the virus go through the mask, but slows and inactivates it," said Michael Strano, a professor at Massachusetts Institute of Technology (MIT) in the US.

The researchers have begun building prototypes and hope to begin testing them soon.

The new design has been described in a paper posted on online preprint server ArXiv, and submitted to a peer-reviewed journal. "The masks that we wear now are designed to capture some of the virus. They do offer protection, but there's no one really thinking about inactivating the virus and sterilising the air. That surprised me," Strano said.

The researchers set out to design a mask that would kill viruses using heat.

They decided to use copper mesh as the heating and capture element, and performed some mathematical modelling to determine the optimal temperature range needed to kill coronaviruses flowing inwards or outwards from natural breathing.

"The vast majority of masks today function by filtration, filtering particles by size or electric charge," said MIT graduate student Samuel Faucher, the lead author of the study.

"This mask relies on a different mechanism and works predominantly by thermal inactivation," Faucher said.

The researchers calculated how rapidly coronaviruses degrade at different temperatures and trapping conditions, and found that a temperature of about 90 degrees Celsius could achieve between a thousandfold and millionfold reduction in viral particles, depending on the final mask size. They also showed that that temperature can be achieved by running an electrical current across a 0.1-millimetre thick copper mesh or thermoelectric heater, powered by a small battery.