The current COVID-19 pandemic has a lot of us thinking about just how dirty the objects we touch every day actually are. Anything that is regularly handled by people is generally crawling with bacteria, and sometimes even viruses. Your smartphone, keyboard, and door knobs are almost certainly filthy. But thoroughly cleaning something like a smartphone can be difficult to do without causing damage. One solution is to use UV-C light to kill bacteria and viruses, and Redditor Prophet_90091 has used a Raspberry Pi to build a UV-C decontamination chamber to do the job.
It’s important to note that UV-C light is far more dangerous than UV-A or UV-B light, and you should not expose yourself, anyone else, or animals to UV-C light. The ozone layer of our atmosphere naturally filters out UV-C light, but artificially generated UV-C is a risk. UV-C light is, however, fantastic for killing the nasty microscopic critters that live on the surface of the items we handle. It’s commonly used to disinfect the surfaces of objects in hospitals and other places where bacteria and viruses — including coronavirus — are a particular concern. This decontamination chamber would, for instance, be great for killing the bacteria living on your computer mouse.
Prophet_90091 built his chamber using a Raspberry Pi, UV-C lamp, a turntable, a continuous rotation servo, a power relay, a buzzer, a reed switch, and some LEDs. When the decontamination chamber is activated, the Raspberry Pi flips the relay on to light up the UV lamp. It then begins spinning the servo to rotate the turntable, which ensures the object inside gets even UV-C light exposure. The reed switch counts the rotations. After the cycle is completed, the buzzer sounds. The cardboard is lined with foil to block and reflect the UV-C rays. The window is just plastic, but that is also capable of blocking UV-C rays so you aren’t exposed. If you want an affordable way to disinfect small items, this build could be worth replicating — just make sure you follow the proper precautions.