Is this the face mask of the future?
Face masks have become a key tool in the global fight against COVID-19 and scientists in Scotland say they've now developed a version that tells the wearer when to stop using it. Masks are mandatory in public spaces across large swathes of Europe as countries attempt to reduce the spread of the virus via air droplets. However, masks need to be replaced regularly in order for them to be effective, and little advice has been given by countries about how long to wear them. Scientists at Scottish co