Eureka moment as HKU develops virus-killing steel

University of Hong Kong researchers have developed the world's first stainless steel that kills the Covid virus.

The team found that stainless steel containing high copper content can kill the coronavirus on its surface within hours, helping lower risks of infection.

The team from HKU's Department of Mechanical Engineering and the Centre for Immunity and Infection spent two years testing the addition of silver and copper to stainless steel and its effect against Covid.

The coronavirus could remain on conventional stainless steel surfaces even after two days, posing "a high risk of virus transmission via surface touching," the team said in the Chemical Engineering Journal.

Stainless steel with 20 percent copper can reduce 99.75 percent of Covid viruses on its surface within three hours and 99.99 percent within six, the researchers said.

It can also inactivate the H1N1 virus and E.coli.

"Pathogen viruses like H1N1 and SARS-CoV-2 exhibit good stability on the surface of pure silver and copper-contained stainless steel of low copper content but are rapidly inactivated on the surface of pure copper and copper-contained stainless steel of high copper content," said Huang Mingxin, who led the research.

The team also tried damaging the surface of the anti-Covid stainless steel as well as wiped alcohol on it and found that it does not change its effectiveness.

They have been liaising with industrial partners to generate prototypes of products such as lift buttons, doorknobs and handrails.

Huang said it "can be mass produced using existing mature technologies.

"They can replace some of the frequently touched stainless steel products in public areas to reduce the risk of accidental infection and fight the pandemic."

But he added that it is hard to estimate the cost products as it will depend on the demand as well as the amount of copper used.

Leo Poon Lit-man, from the Centre for Immunity and Infection of the LKS Faculty of Medicine, who co-led the team, said their research has not investigated the principle behind how high copper content kills the virus.

maisy.mok@singtaonewscorp.com