The Physics of N95 Masks

A standard KN95 mask (product shot)

Have you ever wondered how N95 masks actually work? The general assumption (including my own, before watching this video) is that an N95 mask works like an extremely fine strainer, keeping out any
particles that are bigger than the miniscule gaps in the mesh fibers. Imagine my surprise when said assumption was shattered completely. This video, "The Astounding Physics of N95 Masks," created by Minute Physics, explains that instead, N95 masks work by getting particles—both bigger and smaller than the gaps—to touch and then stick to the mask's fibers. In other words, an N95 mask is more akin to a spiderweb that catches any particles that touch it. The video shows how particles of different sizes move through the fibers, and discusses how N95 masks use an electric field – yes, really – to attract particles. It's only six minutes, but it's a nice and digestible way to learn about how these vital masks work!