Looks like a clever device! Of course, UV-C’s germicidal use has been around for quite a bit. We had a UV-C air sterilizer in my HS biology lab in ‘68 — and the thing was ancient.

That said, there’s some interesting work going on with ‘far’ UV-C. UV-C is 280–100nm, most available UV-C bulbs and LEDs are 260nm or longer. UV-V is germicidal (kills both bacteria and virons by disturbing thymine (the ‘T’ in DNA’s ‘AGCT’) bonds. But humans don’t do well with the ‘near’ UVC those bulbs produce (sunburn, cataracts). That sterilizer I mentioned above had lamps inside and fans to pull air through. But — it looks like the ‘far’ end of UVC (haven’t seen this specified but probably 180–100nm) is still germicidal — but not an issue for us humans (wavelengths that narrow can’t make it through the top layer of our skin, or the layer of tears over our corneas).

So… when we finally get far UV-C lamps, they’ll be safe to leave shining, doing their germicidal thing, making wherever they shine safer (e.g. airports, train stations, supermarkets)

BTW, I recently ordered a couple of UV-C LEDs (265nm) on eBay for under US$20 each. The LEDs are waterproof, look to be intended for water treatment. I plan to DIY a sanitizing cabinet.