PPE

20 Articles

Used Facemasks Turned Into Rapid Antigen Tests With Injection Molding

March 24, 2022 by 15 Comments

Here’s a little eye-opener for you: next time you’re taking a walk, cast your eyes to the ground for a bit and see how far you can go without spotting a carelessly discarded face mask. In our experience, it’s no more than a block or two, especially if you live near a school. Masks and other disposal artifacts of the COVID-19 pandemic have turned into a menace, and uncounted billions of the things will be clogging up landfills, waterways, and byways for decades to come.

Unless they can be recycled into something useful, of course, like the plastic cases used for rapid antigen tests. This comes to us by way of [Ric Real] from the Design and Manufacturing Futures lab at the University of Bristol in the UK. If any of this sounds or looks familiar, refer back to October when the same team presented a method for turning old masks into 3D printer filament. The current work is an extension of that, but feeds the polypropylene pellets recovered from the old masks into a desktop injection molding machine.

The injection molding machine is fitted with 3D-printed molds for the shells of lateral flow devices (LFD) used for COVID-19 rapid antigen testing. The mold tooling was designed in Fusion 360 and printed on an Elegoo Mars MSLA printer using a high-strength, temperature-resistant resin. The molds stood up to the manual injection molding process pretty well, making good-quality parts in the familiar blue and white colors of the starting material. It’s obviously a proof of concept, but it’s good to see someone putting some thought into what we can do with the megatonnes of plastic waste generated by the pandemic response.

Mask DIY sanitization device on the left, mask used as an example on the right. The device is a Tupperware-like plastic container, on top, a small motor plus battery device with an alligator clip attached to the motor. Mask is inserted into the container through the opening on top, hooked to the motor, and the motor then spins the mask inside the container where hydrogen peroxide vapor is being misted.

Mask Sanitization That Anyone Can Build

February 28, 2022 by 10 Comments

We’ve seen a wide variety of mask sanitization solutions, and now, [spiritplumber] from [Robots Everywhere] brings us a frugal and ingenious design – one that you barely even need tools for. This project might look rough around the edges but looks were never a prerequisite, and as a hacker worth their salt will recognize – this is an answer to “how to design a mask disinfector that anyone can build”.

Local shortages of masks have been threatening communities here and there, doubly so if you need a specific kind of mask that might be out of stock. This design could apply to a whole lot of other things where sterilization is desired, too – improving upon concepts, after all, is our favourite pastime.

The design is simple – a battery-powered motor rotating a mask inside a vat of concentrated H2O2, turned into mist by a cheap ultrasonic misting gadget. As the “turntable” rotates a your PPE of choice, making sure that every crevice is graced with cleaning touch of peroxide, it also causes the H2O2 mist to circulate. Fulfilling most important requirements for a proper sanitization system that more complex devices have been struggling with, this approach has certainly earned its place under the sun.

[Robots Everywhere] have shared a small library of their DIY PPE resources with all of us, and that’s not all they work on – recently, we’ve seen their aeroponics project rejuvenating garlic.

Using hydrogen peroxide vapour for PPE sanitization is a well-tested approach by now, as we’ve seen it deployed back in 2020 on a larger scale as part of an FDA-approved design. And if you only have 3% peroxide at hand, might as well try concentrating it further!

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A Surefire Way To Make Masks

January 15, 2021 by 41 Comments

By now, the wearing of a facemask to protect ourselves from pandemic infection is for many of us a daily fact of life. Perhaps that means a cheap disposable mask, but there’s no reason that has to be the case. It’s easy to make more durable masks that can be washed and re-used time and time again, and our Hackaday colleague [Kristina Panos] has shared her pattern and workflow to help you do it.

Her pattern isn’t a complex cut-out but a simple rectangle, and the trick of sewing them together and flipping them inside out makes for a very tidy result. With three pleats pressed in and the elastic sewn up the result is a mask that’s neat, attractive, effective, and cheap, which is a win in our book.

It’s worth repeating her important point that these are not for use in medical environments, instead they’re the standard street-wear aerosol catchers we’re all used to. This isn’t the first time we’ve looked at masks here at Hackaday, or indeed though [Kristana]’s are by far the tidier neither is it first time one of us has made a mask. We looked at them in depth last year in our surviving the pandemic as a hacker series.

From Trash PPE To New PPE

November 9, 2020 by 19 Comments

As the coronavirus pandemic circles the world, a fact of daily life for millions of people has become the wearing of a face mask. Some people sport colorful fabric masks, but for many, this means the ubiquitous Chinese disposable mask. They have become the litter of our time, which as [blorgggg] notes is something that shouldn’t have to be the case. Their plastic can be recycled and made into other useful things, for example, ear savers similar to the ones many of us were 3D printing earlier in the year.

As you might imagine diving into a pile of used masks can be a little unhygienic, so the first step is to disinfect with alcohol. Then the various layers can be separated and the outer polypropylene ones collected and stacked between baking parchment to be melted on a skillet. The result is a polypropylene sheet that can be laser cut if it is thick enough, and from this are cut the ear savers. It’s not quite as neat a cut as the acrylic sheet we may be used to, but it’s adequate for the task.

While on the subject of masks, earlier in the year we presented a series in whose first part we dissected a selection.

Microwave Modified For Disinfecting

July 24, 2020 by 29 Comments

We’re all hopefully a little more concerned about health these days, but with that concern comes a growing demand for products like hand sanitizer, disinfectant, and masks. Some masks are supposed to be single-use only, but with the shortage [Bob] thought it would be good if there were a way to sanitize things like masks without ruining them. He was able to modify a microwave oven to do just that.

His microwave doesn’t have a magnetron anymore, which is the part that actually produces the microwaves for cooking. In its place is an ultraviolet light which has been shown to be effective at neutralizing viruses. The mask is simply placed in the microwave and sterilized with the light. He did have to make some other modifications as well since the magnetron isn’t always powered up when cooking, so instead he wired the light into the circuit for the turntable so that it’s always powered on.

Since UV can be harmful, placing it in the microwave’s enclosure like this certainly limits risks. However, we’d like to point out that the mesh on the microwave door is specifically designed to block microwaves rather than light of any kind, and that you probably shouldn’t put your face up to the door while this thing is operating. Some other similar builds have addressed this issue. Still, it’s a great way to get some extra use out of your PPE.

A Properly Engineered UV Chamber For PPE Sanitization

June 16, 2020 by 49 Comments

Designed to be used once and then disposed of, personal protective equipment (PPE) such as N95 face masks proved to be in such short supply during the early days of the COVID-19 pandemic that getting a few extra uses out of them by sanitizing them after a shift seemed smart. And so we saw a bunch of designs for sanitizing chambers, mostly based on UV-C light and mostly, sad to say, somewhat dodgy looking. This UV-C disinfection chamber, though, looks like a much better bet.

The link above is to the final installment of a nine-part series by [Jim] from Grass Roots Engineering. The final article has links to all the earlier posts, which go back [Jim]’s early research on UV-C sanitization methods back in March. This led him to settle on an aquarium sanitizer as his UV-C source. A second-hand ultraviolet meter allowed him to quantify the lamp’s output and plan how best to use it, which he did using virtual models of various styles of masks.  Knowing that getting light on every surface of the mask is important, he designed a mechanism to move the mask around inside a reflective chamber. The finished chamber, which can be seen in the video below, is 3D-printed and looks like it means business, with an interlock for safety and a Trinket for control.

We love the level of detail [Jim] put into these posts and the thoughtful engineering approach he took toward this project. And we appreciate his careful testing, too — after all, it wouldn’t do to use a germicidal lamp that actually doesn’t emit UV-C.

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PPE Testing Hack Chat

June 15, 2020 by 2 Comments

Join us on Wednesday, June 17 at noon Pacific for the PPE Testing Hack Chat with Hiram Gay and Lex Kravitz!

When the COVID-19 pandemic unfolded in early 2020, the hacker community responded in the most natural way possible: by making stuff. Isolation and idleness lead to a creative surge as hackers got to work on not only long-deferred fun projects but also potential solutions to problems raised by an overloaded medical system and choked supply chains. And so workshops and hackerspaces the world over churned out everything from novel ventilators to social-distancing aids.

But perhaps the greatest amount of creative energy was set loose on the problem of personal protective equipment, or PPE. This was due in no small part to predictions of a severe shortage of the masks, gowns, and gloves that front-line medical workers would need to keep them safe while caring for pandemic victims, but perhaps also because, at least compared to the complexity of something like a ventilator, building a mask seems easy. And indeed it is as long as you leave unanswered the crucial question: does the thing work?

Answering that question is not as easy as it seems, though. It’s not enough to assume that putting some filtration between the user and the world will work; you’ve got to actually make measurements. Hiram Gay and Lex Kravitz, colleagues at the Washington University School of Medicine in St. Louis, actually crunched the numbers on the full-face snorkel mask they modified for use as a face shield for medical PPE, and they have a lot of insights to share about proper testing of such devices. They’ll join the Hack Chat this week to discuss their findings, offer advice to builders, and reveal how they came up with their idea for a different way to build and test PPE.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, June 17 at 12:00 PM Pacific time. If time zones have you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.
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