These last few weeks we’ve all been reminded about the importance of washing our hands. It’s not complicated: you just need soap, water, and about 30 seconds worth of effort. In a pinch you can even use an alcohol-based hand sanitizer. But what if there was an even better way of killing bacteria and germs on our hands? One that’s easy, fast, and doesn’t even require you to touch anything. There might be, if you’ve got a high voltage generator laying around.
In his latest video, [Jay Bowles] proposes a novel concept: using the ozone generated by high-voltage corona discharge for rapid and complete hand sterilization. He explains that there’s plenty of research demonstrating the effectiveness of ozone gas a decontamination agent, and since it’s produced in abundance by coronal discharge, the high-voltage generators of the sort he experiments with could double as visually striking hand sanitizers.
Looking to test this theory, [Jay] sets up an experiment using agar plates. He inoculates half of the plates with swabs that he rubbed on his unwashed hands, and then repeats the process after passing his hands over the high-voltage generator for about 15 seconds. The plates were then stored at a relatively constant 23°C (75°F), thanks to the use of his microwave as a makeshift incubator. After 48 hours, the difference between the two sets of plates is pretty striking.
Despite what appears to be the nearly complete eradication of bacteria on his hands after exposing them to the ozone generator, [Jay] is quick to point out that he’s not trying to give out any medical advice with this video. This simple experiment doesn’t cover all forms of bacteria, and he doesn’t have the facilities to test the method against viruses. The safest thing you can do right now is follow the guidelines from agencies like the CDC and just wash your hands the old fashioned way; but the concept outlined here certainly looks worthy of further discussion and experimentation.
Regular viewers of his channel may notice that the device in this video as actually a modified version of the hardware he used to experiment with electrophotography last year.
Continue reading “Washing Your Hands With 20,000 Volts”
If you’re like most people, then washing clothes is probably a huge pain for you. Figuring out the odd number of minutes necessary to run a wash and dry cycle, trying desperately not to end up with clothes that are still wet, and worst of all having to wait so long for your clothes to be clean can be a real hassle.
One team of inventors decided to build Eleven, a dryer that dries and sanitizes clothes in a minute or less. As explained in their demo video, clothes are placed around the center tube and dried by the airflow initiated by Eleven. Fragrance and ozone is injected to prevent bacteria from causing bad smells.
The team experimented with ultrasonics and microwave-vacuum system, and ultimately decided to use a method that controls the flow of air within the fabric. A steam generator sprays the clothes with a disinfectant while a filter quarantines the chemicals to a receptacle within the device.
They also installed sensors to monitor the performance of the machine remotely, allowing users to track their clothes and the health of the machine even when they aren’t home. Something we’ve previously seen done in the DIY space.
It might not be the futuristic heat-free clothes dryer we were promised, but Eleven certainly looks like a step in the right direction.
One lesson we can learn from the Vietnam War documentary Apocalypse Now is that only crazy people like terrible smells just for fun. Surely Lt. Col. Kilgore would appreciate the smell of 3D printers as well, but for those among us who are a little less insane, we might want a way to eliminate the weird (and not particularly healthy) smell of melting ABS plastic.
While a simple solution would be a large fume hood or a filter to prevent inhaling the fumes, there are more elegant solutions to this problem. [Mark]’s latest project uses an electrostatic precipitator (ESP) to remove the volatile plastic particles from the air. Essentially it is a wire with a strong voltage applied to it enclosed in a vessel of some sort. The voltage charges particles, which then travel to a collecting electrode. Commercial offerings also include an X-ray generator to help clean the air, but [Mark] found this to be prohibitively expensive.
The ESP is built into a small tube through with the air can flow, and the entire device itself is housed in the printing enclosure. The pictures show the corona discharge in the device, and [Mark] plans to test it over the next few months to determine its effectiveness. He does note, however, that the electrostatic discharge creates ozone, which has its own set of problems, so he recommends against building one on your own. Ozone at least still smells like victory.