Six months after the COVID-19 pandemic, the world still doesn’t have N95 respirators (i.e. masks), a product that most people probably didn’t know about before this year. Here in California, we have been using them for wildfire smoke, but generally only for a few days or weeks each year. In normal times, N95 is used in medical settings and then thrown away. But scarcity has required all kinds of innovative ways to allow for sterilization and reuse, to some degree. Now researchers at MIT and Brigham and Women’s Hospital have found a partial solution to the shortage.
The iMASC uses two small, replaceable filter inserts. Image courtesy of MIT.
They have prototyped and are testing an injection molded silicone rubber mask with two replaceable N95 quality filter inserts. Called iMASC, which stands for injection moldable, autoclavable, scalable and conformable, the rubber portion of the mask can be sterilized in many different ways. However, N95 filter inserts have the same drawbacks as traditional N95 masks. They really shouldn’t be reused, but presumably they could be if needed and disinfected properly. The great advantage of iMASC is that it takes much less N95 material to make the two filters smaller than a full N95 respirator.
The idea of a rubber and plastic respirator with replaceable filters is not new. Browsing the 3M site literally produces pages of commercial grade respirators and dozens of different filter cartridge options, from N95 to P100 and vapor filters. However, they have a major drawback that makes them a problem for use against COVID-19: they filter the air you inhale, but not the air you exhale. After all, they are made to protect the user from the environment, not the other way around. Several of my friends who own them for their business have modified them by adding a filter to the exhaust valve, but that’s not a great option for the mass market.
The team at MIT and Brigham and Women’s Hospital started from the shape and design of a disposable model, the 3M N95 1895 respirator, which was already in use at the hospital. Their goal was to get an equivalent fit, but in a reusable, economical form factor.
An initial test with 24 healthcare workers went well, with positive comments on fit and breathability. It also successfully leaked a test spray. The masks are expected to cost hospitals around $ 15 each once they are in production, and should be reusable up to 100 times. The team expects the filters to cost less than a dollar. At the current $ 3- $ 10 cost currently inflated for the N95 disposable masks, that seems like a very good option. Of course, when I bought 3M N95 wildfire smoke respirators in 2017, they cost $ 0.75 each, even in small quantities.
The researchers are working on a new version and plan to create a company to produce and sell them. Right now, it sounds like a great idea for a business, but it’s hard to believe 3M doesn’t have a ton of similar designs in progress based on minor modifications to their existing offerings. Therefore, your startup will clearly have its work for it.
[Featured image credit: MIT]Now read:
