What is what does foil on doorknob do?

A foil on a doorknob can be used to prevent static electricity from accumulating in your body and discharging through the doorknob. This is particularly useful during winter, when you wear woolen clothing and the air inside your home can become dry. The foil acts as a conductor, allowing the static electricity to discharge through it instead of through your body, which can cause a painful shock. Additionally, the foil on a doorknob can help prevent the spread of germs or viruses, as it provides a nonporous surface that is easy to sanitize or disinfect.