The Benefits Of Displacement Ventilation

The world has been shaken to its core by a respiratory virus pandemic. Humanity has been raiding the toolbox for every possible weapon in the fight, whether that be masks, vaccinations, or advanced antiviral treatments.

As far as medicine has come in tackling COVID-19 in the past two years, the ultimate solution would be to cut the number of people exposed to the pathogen in the first place. Improving our ventilation methods may just be a great way to cut down on the spread. After all, it’s what they did in the wake of the Spanish Flu.

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Turning Old Masks Into 3D Printer Filament

Disposable masks have been a necessity during the COVID-19 pandemic, but for all the good they’ve done, their disposal represents a monumental ecological challenge that has largely been ignored in favor of more immediate concerns. What exactly are we supposed to do with the hundreds of billions of masks that are used once or twice and then thrown away?

If the research being conducted at the University of Bristol’s Design and Manufacturing Futures Lab is any indication, at least some of those masks might get a second chance at life as a 3D printed object. Noting that the ubiquitous blue disposable mask is made up largely of polypropylene and not paper as most of us would assume, the team set out to determine if they could process the masks in such a way that they would end up with a filament that could be run through a standard 3D printer. While there’s still some fine tuning to be done, the results so far are exceptionally impressive; especially as it seems the technique is well within the means of the hobbyist.

From masks to usable filament.

The first step in the process, beyond removing the elastic ear straps and any metal strip that might be in the nose, is to heat a stack of masks between two pieces of non-stick paper with a conventional iron. This causes the masks to melt together, and turn into a solid mass that’s much easier to work with. These congealed masks were then put through a consumer-grade blender to produce the fine polypropylene granules that’re suitable for extrusion.

Mounted vertically, the open source Filastruder takes a hopper-full of polypropylene and extrudes it into a 1.75 mm filament. Or at least, that’s the idea. The team notes that the first test run of filament only had an average diameter of 1.5 mm, so they’re modifying the nozzle and developing a more powerful feed mechanism to get closer to the goal diameter. Even still, by cranking up the extrusion multiplier in the slicing software, the team was able to successfully print objects using the thin polypropylene filament.

This is only-during-a-pandemic recycling, and we’re very excited to see this concept developed further. The team notes that the extrusion temperature of 260 °C (500 °F) is far beyond what’s necessary to kill the COVID-19 virus, though if you planned on attempting this with used masks, we’d imagine they would need to be washed regardless. If the hacker and maker community were able to use their 3D printers to churn out personal protective equipment (PPE) in the early days of the pandemic, it seems only fitting that some of it could now be ground up and printed into something new.

Fight Disease With A Raspberry Pi

Despite the best efforts of scientists around the world, the current global pandemic continues onward. But even if you aren’t working on a new vaccine or trying to curb the virus with some other seemingly miraculous technology, there are a few other ways to help prevent the spread of the virus. By now we all know of ways to do that physically, but now thanks to [James Devine] and a team at CERN we can also model virus exposure directly on our own self-hosted Raspberry Pis.

The program, called the Covid-19 Airborne Risk Assessment (CARA), is able to take in a number of metrics about the size and shape of an area, the number of countermeasures already in place, and plenty of other information in order to provide a computer-generated model of the number of virus particles predicted as a function of time. It can run on a number of different Pi hardware although [James] recommends using the Pi 4 as the model does take up a significant amount of computer resources. Of course, this only generates statistical likelihoods of virus transmission but it does help get a more accurate understanding of specific situations.

For more information on how all of this works, the group at CERN also released a paper about their model. One of the goals of this project is that it is freely available and runs on relatively inexpensive hardware, so hopefully plenty of people around the world are able to easily run it to further develop understanding of how the virus spreads. For other ways of using your own computing power to help fight Covid, don’t forget about Folding@Home for using up all those extra CPU and GPU cycles.

Two views of the M19O2 oxygen concentrator

Design Improvements Make DIY Oxygen Concentrator Even Better

A lot of projects we feature on these pages are of the “one and done” variety — tactical builds that serve a specific purpose with little need for further development. Some projects, though, come out as rough prototypes and then go through multiple rounds of refinement, a process we really enjoy tracking down and following. And when the project is something as important as an oxygen concentrator that can be built and maintained easily, all the better.

The need for cheap oxygen concentrators stems directly from the COVID-19 pandemic, which suggested that high-flow oxygen therapy was a better choice than invasive intubations and mechanical ventilation. But medical-grade oxygen isn’t always easy to come by in all parts of the world, so easily built oxygen concentrators, which rely on the nitrogen-adsorbing properties of the mineral zeolite, are meant to fill the gaps. Early versions of the M19O2 and the related OxyKit concentrator, had a very homebrew feel to them, built on wooden frames as they were. And while the rustic nature of the early builds didn’t detract from their utility, the hackers behind them, including our own [Anool Mahidharia], have been making incremental improvements aimed at not only making the devices work better, but also making them easier to build.

The hackers at Maker’s Asylum have done a fantastic job at documenting their work, with everything posted to a GitHub repo so that anyone can undertake a build. And really, for something as important as making oxygen when it’s needed, there’s really no reason not to give this a try.

Reminder: Bring-A-Hack Is This Thursday August 5th

Hey you! What have you been working on lately? No, wait, don’t tell us just yet! Save the juicy details for the summer edition of Bring-A-Hack. It’s going down in just two days — that’s Thursday, August 5th at 1:00 PM Pacific Daylight time (4pm EDT | 9pm BST/CET). Go register right now!

Historically, Hackaday has attended (or hosted) Bring-a-Hack events as a social activity along with live conference. You grab something off your bench and it gives you a thing to talk about as you see friends old and new. This virtual Bring-a-Hack walks in those footprints — anyone who wants to present their to the group can just type ‘I would like to present’ in the Crowdcast chat once the event gets under way. We also plan to have breakout rooms for more interaction.

If you were too shy to show off one of your projects at the last one of these back in April, now is your chance! Are you building something for the Hackaday Prize? What have you done to make working from home more tolerable? Whatever you’re into, we want to see it, so come and show it off to the hacker elite from around the world. And just because they’re elite, it doesn’t mean they’re elitist: it doesn’t matter what level your project is on. What matters is that you’re passionate about it, and that you probably learned something along the way — something you can share with the community that will bring you many virtual pats on the back.

So go and get registered, shine up those hacks, and we’ll see you there!

No Mask Required: Bring-A-Hack Is Back August 5th

Yes, we’re still in a pandemic and yes, these types of events are still happening over videoconference and not in meat space. But you know what? That means that so many more people have the opportunity to show up and show off their hacks! As long as 1 PM PDT is within your personal uptime, that is. Maybe you can make an exception if not?

Here is your link: the summer edition of Bring a Hack with Tindie and Hackaday will take place on Thursday, August 5th at 1:00 PM Pacific Daylight time (that’s 4pm EDT | 9pm BST/CET). Choose your gnarliest hack of late and go register for the event, which will be held on the Crowdcast video chat platform this time around.

The remote Bring-A-Hack held way back in April was packed with awesome people. Now is your chance to join in! You all have awesome projects from the last few months (we’ve seen a lot of them on these very pages), so come show them off to the hacker elite from around the globe. You know the deal: it really doesn’t matter what level your project is on, so don’t worry about that. As long as you’re passionate about it, we’d love to see it and hear all about the problems you had to overcome and yes, even the mistakes you made. You never know what knowledge you might have that can push someone else’s project over the finish line.

Shine up your hacks, and mark those calendars; here’s a timezone converter if you need it. Reserve your spot now. Seriously, don’t fool yourself into thinking your build isn’t impressive enough — we want to see it. My hack might not even involve a circuit, and that’s enough to pique your interest, right? See you there!

Open-Source Oxygen Hack Chat

Join us on Wednesday, May 5 at noon Pacific for the Open-Source Oxygen Hack Chat with Maher Daoudi and the OxiKit Team!

In such tumultuous times, it may be hard to remember last week, let alone last year. But if you dig back a bit, you may recall what a panic the world was in at this point in 2020 about the ventilator crisis. With COVID-19 cases on the rise and the potential for great numbers of patients needing intensive care, everyone and their brother was hacking together makeshift ventilators, in the well-intentioned belief that their inventions would help relieve the coming shortage of these lifesaving medical mechanical miracles.

As it came to pass, though, more COVID-19 patients have benefited from high-flow oxygen therapy than from mechanical ventilation. That’s great news in places where medical oxygen is cheap and easily available, but that’s always the case. We’ve seen recent reports of hospitals in India running out of oxygen, and even rural and remote areas of the developed world can find themselves caught without enough of the vital gas.

To meet the world’s increasing demand for high-flow oxygen therapy, the team at OxiKit has developed an open-source oxygen concentrator that can be built for far less than what commercial concentrators cost. By filtering the nitrogen out of the air, the concentrator provides oxygen at 90% or higher purity, at a flow of up to 25 liters per minute.

Oxikit founder Maher Daoudi and some of the technical team will join us for this Hack Chat to discuss the details of making oxygen concentrators. We’ll learn about how they work, what the design process for their current concentrator was like, and how they got past the obstacles and delivered on the promise of high-flow oxygen for the masses.

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, May 5 at 12:00 PM Pacific time. If time zones have you tied up, 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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