American Scientist

July-August 2012

Volume: 100 Number: 4

A time-lapse photograph shows discharges of static electricity from the tines of a fork to four metal electrodes. Charges on the electrodes create this electrostatic induction discharge. Most people have had a similar experience when scuffling across a carpet in dry weather and then touching a metal object, such as a doorknob. In such a case it is the rubbing against the carpet that creates the charge buildup, which is known as triboelectric or contact charging. What actually causes triboelectric charging has been demonstrated to depend on the materials involved, and it has been suggested that more than one mechanism can be at play. In “What Creates Static Electricity?”, Meurig W. Williams explains that a number of researchers are actively exploring the topic, and the results are still coming in. Static charges can often be a nuisance, causing problems for electronic equipment. But when the charges are properly harnessed, they are the basis of such useful products as copiers and laser printers. Williams notes that the history of toners in copiers is also convoluted and controversial.