Aaron Collins is standing in his bathroom, holding a white mask to his face while stretching its straps to the back of his head.
Here in the "lab" at his Minneapolis home, Collins is launching experiment No. 520 — the latest installment in his 18-month quest to help people use masks for better protection against COVID-19.
Just a few minutes earlier, Collins turned off a machine whirring like an air compressor that's perched at the edge of his bathroom sink. A clear tube leads from the mask he's wearing to a separate piece of scientific equipment sitting on the window sill.
Collins, 37, points excitedly to the screen on his laptop where a squiggly line has suddenly fallen like a rock.
"This is really a high-performing mask," he says on this mid-February afternoon, wearing a red-and-black checked shirt that's like many he wears on his YouTube channel...
