A Chinese welder, dubbed "China's useless Edison", has made a stainless steel mask due to the shortage of face masks during the COVID-19 outbreak. The video, provided by the 32-year-old welder named ...

Homemade masks that used flimsier fabric tested as low as 1 percent filtration, Dr. Segal said. The best-performing designs were a mask constructed of two layers of high-quality, ...