[Wired] Scientists Put Masks to the Test—With a Cell Phone and a Laser

[Wired Magazine]

Scientists Put Masks to the Test—With a Cell Phone and a Laser

Not all face coverings—like masks, bandanas, and neck gaiters—are equally good at blocking germs. A new, low-cost testing device literally illuminates the difference.

https://www.wired.com/story/scientists-p...nd-a-laser