What is foil around doorknobs?

Foil around doorknobs is sometimes used as a method of preventing static electricity from building up and potentially damaging sensitive electronic equipment or components. The foil creates a conductive path to the ground, helping to discharge any static electricity that might be present. This technique is particularly common in cleanrooms, where even small amounts of static electricity can disrupt delicate manufacturing processes. Additionally, some people may use foil around their doorknobs as a low-tech way of preventing germs and viruses from spreading, as the foil can act as a barrier that traps any contaminants present on the surface of the knob.