UVC banana and rubber test

A project log for naminukas

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Mykolas JuraitisMykolas Juraitis 07/13/2020 at 08:201 Comment

Last week I have added a small UVA+UVC LED to naminukas. While I emphasized in the video that disinfecting function is just a proof of concept and in the final product more powerful ultraviolet lamps should be used, I got a few comments saying that a lot of UVC LEDs are fake and I should do a banana test. Banana skin is supposed to get darker under UVC light. While testing with bananas I also noticed that nitrile rubber tire near LED got cracked:

Hopefully that proves that from sufficiently short distance my LED would kill bacteria too. I will need to replace rubber tire with silicone which is UV resistant.

On the next day, an area surrounding darkened spot got darker too:

UVC irradiated bananaI wonder if it is because of stray UV light or the original spot caused surrounding area to ripen faster. I you know more about UV exposure effects please let me know in the comments.


John Loeffler wrote 07/13/2020 at 18:36 point

I would Try green bananas at a distance far enough away that heating effect would not work.  Making it would also give you a better contrast see this video (

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