• Question: how do you make the special coating?

    Asked by 472heak37 to Kath on 6 Nov 2017.
    • Photo: Kathryn Thomas

      Kathryn Thomas answered on 6 Nov 2017:

      I use a process called magnetron sputtering if you want to look it up in more detail.
      Basically, all the coatings I use are made of glass so first I have to make a round piece of glass by melting different salts and other compounds together.
      Then I put the glass and all the metal disks I want to coat into the sputtering machine, which is a big metal sealed box (chamber) with lots of pumps and sensors attached. All the air is pumped out of the chamber where the sputtering is going to happen and then Argon gas is pumped in so we know exactly what is going to happen in the chamber and there are no unexpected reactions.
      The Argon molecules are forced to hit the glass, and basically ping small glass molecules off the surface so they fly round the chamber and land on the metal disks (and also everything else). I can control the thickness of the coating my how long I leave the machine on. I can also change what I coat by changing the glass I use.
      It’s pretty cool because it’s only my lab here in Nottingham and one other lab in Romania coating glasses using this method. Thank you for your question!