Using virus-killing material in air filters could help reduce the spread of disease

As variants of the coronavirus are proving more easily transmissible, a made-in-New-Brunswick research project could help slow the spread. 

Felipe Chibante, a professor of chemical engineering at the University of New Brunswick, has successfully embedded tiny bits of virus-killing particles into material which can be used to make masks and air filters. 

"We are now making those materials and finding that yes, they do work, they are capable of sterilizing material," said Chibante. "Now we just have to validate that with testing."

Using that material, his team has developed a prototype of a mask, but the potential goes well beyond masks. 

Chibante said the technology could be used to develop air filters that could work with existing air-exchange systems. 

Like a lot of things related to the novel coronavirus, the science around its spread has evolved over the last year. 

Scientists initially believed the virus spread primarily through heavy droplets from a sneeze or a cough, which quickly fall to the ground. Research eventually revealed that airborne transmission also exists.

Airborne transmission involves smaller particles that travel through the air longer and farther, which is why the virus spreads more easily in poorly ventilated spaces. 

Last week, the province's chief medical officer of health said her department had recommended that the University of New Brunswick make "minor changes" to the ventilation system of a residence that had experienced an outbreak of a variant of concern. 

Dr. Jennifer Russell said the step was a precaution to ensure that airflow hadn't been contaminated in the building. 

As of Friday, there were 12 positive cases linked to Magee House, which involves a particularly concerning — and easily transmissible — variant first identified in India. 

Russell said the next round of testing will help public health officials determine whether aerosolized, or airborne, particles have spread through the ventilation system. 

Chibante said his research proposal wasn't "a one-trick pony." 

"It was never just about the masks. We looked at this as being able to solve a bigger issue."

His initial research proposal included using the material in building ventilation systems.

"It would be something that doesn't just trap the contagions, but actually kills them." 

He said his team could "develop that fairly quickly after the summer."

His project is also working on a second-layer of protection for masks and filters. While the nano-sized metals kill most of the virus particles on contact, they don't kill them all. 

To effectively sterilize the masks or filters and make them truly reusable, Chibante's team is working on a secondary step. 

Building on his work in the energy sector, he hopes to create a self-sanitizing feature for the masks and filters.

Since pathogens can usually be destroyed at temperatures above 60 C, he wants to use tiny electrical systems to create enough heat in the material to destroy anything that wasn't already killed on contact with the anti-viral metal particles. 

He said it could be as easy as plugging the mask into a USB port that would heat the material to the proper temperature for about 15 minutes. 

He said it's almost like a tiny toaster element inside the material. 

Other applications

The same could be done for air filters. He said the system would be able to detect a buildup of pathogens and then automatically activate the heating cycle. That way, filters don't have to be changed every day. 

Since he first proposed the project in the early days of the pandemic, the idea has attracted the attention of the Department of National Defence, which has contributed funding to explore wider applications of the technology. 

Although mask prototypes are ready, Chibante said there's still a lot of work and testing to be done before they're available commercially.  

While the world awaits the end of the current pandemic, Chibante said there will always be a use for the technology. 

"It's not just for COVID or other SARS-type issues," he said. 

It also has applications for all airborne biological pathogens, including legionnaires' disease, which sent 15 people to hospital in Moncton following an outbreak in 2019. 

The power of nano-particles

Chibante and his team worked with several metals that have already proven their antibacterial and antiviral properties. Copper for example, has long been known to disrupt or kill pathogens, which include bacteria, viruses, or other microorganisms that can cause disease.

He said they're leaning toward using copper, since it's effective and safe for human contact. 

"We actually use copper in our systems," he explained. "We metabolize it, we consume it, we use it, so copper is something that we're leaning toward."