Aaron Collins is standing in his bathroom, holding a white mask over his face while stretching its straps to the back of his head.
Here in the “laboratory” of his Minneapolis home, Collins is launching Experiment #520 – the latest installment in his 18-month quest to help people use masks for better protection against COVID-19.
Minutes earlier, Collins turned off a machine that was humming like an air compressor perched on the edge of his bathroom sink. A transparent tube connects the mask he wears to separate scientific equipment on the windowsill.
Collins, 37, excitedly points to her laptop screen where a wavy line has suddenly fallen like a rock.
“It really is a very capable mask,” he says on this afternoon in mid-February, wearing a red and black checkered shirt like many others he wears on his YouTube channel.
Before the big drop, the bumpy line on the computer screen illustrated the high concentration of sodium chloride particles, which were being pumped throughout the bathroom by the aerosol canister near the sink.
As they should with good masks, the readings from the machine near the window – called a particle counter – plunged once Collins fitted the mask snugly to his boyish face.
Then Collins enters the results into a spreadsheet that he freely shares online – a gold star issued by the self-proclaimed “mask nerd”.
“I just want better masks on more faces,” he says. “If you know the secret – if you know any information that could help people – it’s your moral obligation to make sure people are aware of it.”
Mask nerd has mass appeal
Before the pandemic, Aaron Collins was no nerdy with masks. He was simply a mechanical engineer with a background in aerosol science.
In addition to spending time with his wife and their now 6-year-old child, Collins enjoyed riding bicycles and using a treasure trove of second-hand science equipment in his basement for hobbies such as measuring the quality of the air inside his house.
But as COVID-19 spread, Collins wanted to know which masks offered the best protection against infection. He started testing different models in the summer of 2020 and shared his results through more than 40 videos on YouTube.
On Twitter, his @masknerd account has over 48,000 subscribers. The mask nerd’s work has been featured everywhere, from the Wall Street Journal and the National Public Radio Marketplace to CBS Mornings with Gayle King.
Many videos feature long live streams as he actively tests masks from inside his bathroom – a recent video is over three hours long. Others are shorter and provide summaries or thematic reviews. A video survey mask option for kids has over 250,000 views.
Earlier this year, Collins released several videos titled “Mask Nerd Shorts” to address common issues such as spotting counterfeits and making sense of alphabet soup with better performing N95, KN95 and KF94 masks.
Its awkward authenticity is endearing.
“Welcome back to another Mask Nerd Short. Today, why do I always say: Face-fit! Face-fit! Face-fit!” he says in a video.
In early 2021, videos made by Collins began to attract the attention of researchers at the University of Minnesota. Now, when Neil Carlson, an industrial hygienist at U, offers advice on finding good masks, the mask nerd’s videos are among the resources he highlights.
He credits Collins, in particular, for helping people learn about popular better performing masks in South Korea, which Carlson says are a good option for Americans.
“I really appreciate what Aaron has done,” Carlson said. “One man’s mission to educate people about masks and respirators has helped many people through this pandemic.”
A classroom connection too
Last year, Collins worked with parents to place air purifiers in her son’s elementary school classrooms. He helped get buy-in from school officials by portraying the idea in a non-confrontational way, said Katie Shepherd, one of the parents who worked on the project.
Shepherd, who is immunocompromised, described Collins’ friendly style while offering her personalized mask advice.
“He just has this way of helping people understand, without them feeling ignorant or feeling bad,” she said.
In the fall, Collins hosted an online session for parents grappling with the pandemic challenge of finding masks that work well for children. He brought samples of masks to his son’s school that children are more likely to wear, said Angela Peña, a second-grade teacher.
“His wit and silliness can make his message so appealing,” Peñasaid said. “People want to listen and learn.”
In her day job, Collins does not work on masks. He is a senior process engineer, specializing in nano- and micro-assembly, in a company that manufactures computer hard drives. Collins also has extensive industry experience in the field of aerosol science.
That experience, along with her graduate work at the U, gives Collins the know-how for the task of testing the masks. Long before the pandemic, he regularly shopped at websites like eBay looking for bargains on used science equipment.
“It was really kismet — I literally had everything you needed in your basement to test the masks on,” Collins said. “I didn’t know if the KN95 mask I was using was any good, and I kinda lamented it, and my wife looked at me and said, ‘Why don’t you test it? “”
Rather than take the time to write up the test results, Collins opted to simply livestream his experiments and post a spreadsheet with all the data online. It’s faster that way, he said, and it also helps with transparency because people can see his methods.
Manufacturers supply many of the masks he tests. Collins points out, however, that he does not receive any payment from third-party companies or distributors. He welcomes the skeptical response some might have when first encountering his work.
“If you saw a random guy on the internet that said, ‘Oh yeah, I’m testing masks,’ you’d be like, ‘Yeah, good buddy,'” Collins said. “So, hey, don’t trust me. I’ll explain why my data is good and present the evidence to you – and you can decide whether you want to believe me or not.”
After performing more than 500 tests on more than 200 different mask designs, Collins has become a go-to source of wisdom on personal protective equipment. Even so, he found the attention surprising.
When reflecting on the personal thrill of being interviewed by King of CBS Mornings, he jokes that he could have called her, “I’m a nerd! You shouldn’t talk to me! I do stuff in my room bathroom — why are you talking to me?
The bathroom is his laboratory, by the way, because it’s the smallest room in the house. As such, it is the easiest to fill with sodium chloride particles for the filtration efficiency measurements it performs on masks.
“It’s salt particles,” he explains when setting up Experiment #520. “You would breathe more if you were sitting near the ocean.”
There are masked nerds in all walks of life, and “they’re a force for good,” Collins said. His goal with the videos, initially, was simply to provide good test data to fellow enthusiasts.
This way they could spread out and spread the gospel of masked nerds.
“That’s why we’re scientists. That’s why we’re engineers. We’re not in it for the money. … We’re in it because we have a passion to change the world for the better.”