We often find ourselves around materials that we take for granted, I certainly do take plastics, building materials like concrete are almost ubiquitous. so i found myself investigating glass in its may types and forms: windows, coffee tables, shower doors, containers, car windscreens.
When we started this project i had no idea that i would have to become fluent in some glass technology. Glass is made of some very basic plentiful compounds (sand, soda ash and limestone) and we needed a glass “window” to protect the UVC leds from being contaminated by the covid virus or other pathogens. Using a plastic sheet would not be suitable in this context because it would essentially melt the plastic (rather it would change the chemical composition and the plastic window would eventually turn into powder) so it would not be a good solution. Normal silica (sand) based glass, while improving the life of the cover also would not be suitable. Why not? its glass? that should work right? that’s what i thought. so while glass around you lets the visible wavelength through it also stops other wavelengths that we can’t see, like erm….UltraViolet (or UV light).
well, the challenge is created by the type of transmitted light being able to penetrate through the window. UVC will not penetrate silica glass. However there is a type of glass that allows UVC to pass through unhindered – it is called quartz glass. I purchased samples which were 15mm diameter by 1mm thin. The mask has 4 LEDs to expose the virus to DNA-Melting UV light at a certain wavelength.
I always try to think of things visually in the real world. for instance, if you have seen any drone video looking down on a crowd of people, say dancing in New Orleans Mardi Gras. That, to me, would conjure up a real world example substituting people, dancing in the streets, for atoms in a sheet of normal glass. then a certain wavelength (in this case the UV) might be a UPS delivery person trying to make a delivery of a large bulky box to the other side of the street while everyone is still dancing. the chances of the delivery person making it to the other side is certainly possible….most likely in both this simulation and the real world, they will probably try again another day 🙂 the street, with all the dancing stops the delivery because its just too much hassle and too much energy to bother. In contrast the glass stops the UV if its not made of the correct material.
It is sometimes difficult to visualize concepts in a real world setting but it helps me because i just think visually, it doesnt suit everyone. Anyway, i did find it fascinating about glass, its makeup, manufacturing and the deep thinking from the thousands of people now and in the past, that have gone into making something that we so easily takes for granted. A piece of material that we can see through.
Today, we can obtain many types of glass: hardened, tempered, sealed, optical, you have come into contact with all of them, though you may not know it…try to think which ones you have used? right, back to the mask and its development!