Scientists say they have invented a face mask that can tell you if COVID-19 is in the air.
The mask uses a biosensor that can detect respiratory viruses in air droplets, according to a study published in peer-reviewed science journal Matter.
The sensor attached to the mask detected as little as 0.3 microlitres of liquid containing the virus, about 70 to 560 times less than the volume of liquid produced in one sneeze.
It then sends a phone alert to the wearer to tell them they have been exposed.
Conventional face masks have been proven to reduce the risk of COVID as a barrier and filter to pathogens and germs.
The study's co-author, Dr Yin Fang from Shanghai's Tongji University, said the bioelectronic mask could be adapted to detect emerging viruses, and prevent future outbreaks.
"Our mask would work really well in spaces with poor ventilation, such as elevators or enclosed rooms, where the risk of getting infected is high," he said.
The sensor uses synthetic molecules that can be designed to target specific pathogens — in this case, COVID and two influenza strains.
If these are detected, a wireless device embedded in the mask sends an alert to the wearer's phone.
Similar technology was used by researchers at a Harvard laboratory in the US, where biosensors were embedded in N95 masks to create an in-built COVID test.
University of Technology Sydney infection control expert Marilyn Cruickshank said this latest development from China was a "promising first step", but its success would depend on how it was rolled out.
"I can see that there is great potential, but it would need some good education and implementation strategies — like most novel approaches, it's all about implementation," she said.
"People have to wear them, they have to know what they need to do if they are exposed to do it — because knowing that you've breathed it in is only the first step.
"There needs to be a whole process behind what happens if you get this result."
Dr Yang said the new masks would help doctors diagnose illnesses faster.
"Currently, doctors have been relying heavily on their experiences in diagnosing and treating diseases," he said.
"But with richer data collected by wearable devices, disease diagnosis and treatment can become more precise."
