Today we answer an important question: “How do I coat things in metal; even things that don’t want to be coated in metal?” You want to plate gold onto you Sacajawea dollar, that’s easy enough. You can use electricity to get one metal to stick to another. You want to cover Jill Masterson you use gold paint. But let’s say you’ve got a little plastic doohickey you want to look at under an SEM. Plastic famously refuses to conduct electricity. So how do you defeat the charging problems? (The charging problems that we mentioned last time. You were paying attention, weren’t you?) The answer is you sputter coat it. And this week I’ll be explaining what that means.
Start with an Argon plasma. Hmm… maybe let’s start a little earlier than that. A plasma is a gas where the atoms have an electron stripped off. Also, the stripped off electrons. You’ve got to keep your plasma at a pretty high energy, otherwise your atoms recapture their electrons and you end up with a boring ol’ gas. If you’re the Sun then you can make a plasma by heating up these gases to an enormous temperature. On Earth that’s less convenient, so we use electricity.More