As punters return to the workplace, airborne transmission of COVID-19 via air-conditioning systems could pose a significant threat. Scientists have now developed a prototype air filter made from nickel foam which kills COVID-19 on contact.

Researchers — after figuring out that the virus cannot tolerate temperatures above 70°C — have fabricated and tested prototype heated nickel foam filters which catch and kill SARS-CoV-2.

Results of the study revealed that 99.8 per cent of the ‘aerosolised’ (converted into fine spray) SARS-CoV-2 was caught and killed by a single pass through a nickel filter heated up to 200°C.

Heating is localised on the nickel foam and heat transfer to the passing air is minimal, researchers say.

Commercial nickel foam is electrically conductive, strong, and flexible; properties that have prompted its wide use in energy conversion and storage applications.

But in this case, nickel foam’s most important attribute is the randomly located pores between 50 and 500 μm in size that meander from one side of the foam to the other.

This — unlike traditional air conditioner filters based on fiberglass or aluminium — results in a very large surface area that can effectively catch particles in the air passing through the filter.


Reducing the risk

This tech paves the way for preventing transmission of COVID-19 and other highly infectious airborne agents in closed environments like offices and gyms, according to the study.

“The deployment of these novel filter and purification units stands to have a dramatic impact on both essential workers and the general public in the current COVID-19 pandemic, as well as reducing the risk of exposure to other airborne highly infectious agents, both known and unknown,” according to the study.

“With a phased rollout, beginning with high-priority venues where essential workers are at elevated risk of exposure (particularly hospitals and health-care facilities, as well as public transit environs such as airplanes), this innovative technology will:

(a) improve the safety for frontline workers in essential industries by minimising the risk of SARS-CoV-2 exposure,

(b) make it possible for non-essential workers to safely return to public workspaces by reducing their risk of exposure, and

(c) allow for the general public to more safely reengage with their own communities through the creation of mobile air-purification devices that can be carried on one’s person to maintain clean personal air space.”

The air purification and disinfection system derived from this nickel foam-based heated filter will also be a useful addition in the “armamentarium of technologies” available to combat future pandemics, researchers say.