HOUSTON: Scientists have designed a “catch and kill” air filter which they say can trap the novel coronavirus and neutralise it instantly, an invention that may reduce the spread of Covid-19 in closed spaces such as schools and hospitals, as well as public transit environments like airplanes. According to the study, published in the journal Materials Today Physics, the device killed 99.8 per cent of the novel coronavirus, SARS-CoV-2, in a single pass through its filter.
It said the device, made from commercially available nickel foam heated to 200 degrees Celsius, also killed 99.9 per cent of the spores of the deadly bacterium Bacillus anthracis which causes the anthrax disease. “This filter could be useful in airports and in airplanes, in office buildings, schools, and cruise ships to stop the spread of Covid- 19,” said Zhifeng Ren, a co-author of the study from the University of Houston (UH) in the US.
According to the scientists, since the virus can remain in the air for about three hours, a filter that could remove it quickly was a viable plan. The study noted that the coronavirus cannot survive temperatures above 70°C, so by making the filter temperature far hotter — about 200°C, researchers said they were able to kill the virus instantly.
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,” researchers noted. By making the filter electrically heated, rather than heating it from an external source, they said the amount of heat that escaped from the filter is minimised, allowing air conditioning to function with very low strain. When the scientists built and tested a prototype for the relationship between voltage/current and temperature, they said it satisfies the requirements for conventional heating, ventilation, and air conditioning (HVAC) systems, and could kill the coronavirus.