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Scientists have developed a “catch and kill” air filter which can supposedly trap the novel coronavirus and instantly neutralise it. This invention might just be able to reduce the spread of covid-19 in closed spaces such as schools, hospitals and health care facilities, and even in public transit environments like airplanes.
The study has been published in the journal Materials Today Physics and it suggests that the device can kill 99.8% of the novel coronavirus, SARS-CoV-2, in a single pass through its filter.
The device is made from commercially available nickel foam which is heated to 200 degrees Celsius. It is also said to kill 99.9% of the spores of Bacillus anthracis–the deadly bacterium which causes the anthrax disease.
Co-author of the study from the University of Houston (UH) , US, Zhifeng Ren says,
This filter could be useful in airports and in airplanes, in office buildings, schools, and cruise ships to stop the spread of covid-19.
“Its ability to help control the spread of the virus could be very useful for society,” Ren added.
The researchers mentioned that they were also developing a desk-top model for the device that would be used to cleanse the atmosphere around an individual in the office. The scientists believe that since the virus can remain in the air for about three hours, having a filter to quickly remove it was a viable plan. And considering the fact that economies are reopening across the world and that businesses are having to start working again, controlling the spread in air-conditioned spaces was urgent.
Observations from the study indicate that the novel coronavirus cannot survive temperatures above 70 degrees Celsius, so by making the filter temperature about 200 degree Celsius, they were able to kill the virus almost instantly.
Ren said the nickel foam met several key requirements.
“It is porous, allowing the flow of air, and electrically conductive, which allowed it to be heated. It is also flexible,” the researchers noted in a statement.
However, they also said that nickel foam had low resistivity and that makes it difficult to raise the temperature high enough to quickly kill the virus.
The researchers added that they solved this problem by folding the foam, connecting multiple compartments with electrical wires to increase the resistance high enough to raise the temperature as high as 250 degrees Celsius.
When the filter electrically heated, rather than being heated from an external source, the amount of heat that escapes from the filter gets minimised: this allows air conditioning to function without much strain on it.
“This novel biodefense indoor air protection technology offers the first-in-line prevention against environmentally mediated transmission of airborne SARS-CoV-2, and will be on the forefront of technologies available to combat the current pandemic and any future airborne biothreats in indoor environments,” said Faisal Cheema, another co-author of the study from UH.
The researchers have called for a phased roll-out of the device, “beginning with high-priority venues, where essential workers are at elevated risk of exposure.”
They believe the novel device will not only improve safety for frontline workers in essential industries but will also allow nonessential workers to return to public workspaces.
(With inputs from PTI)