disinfection

3 Articles

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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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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