Static charging: old and new mysteries

This article introduces the history and theory of static electricity and some recent results on the mechanism of static charging. The mechanism is still a mystery, but in the last two decades, scientists including Arthur F. Diaz of IBM and George Whitesides and his group at Harvard have made major progress on the problem: they provided evidence for a surprising mechanism, which requires non-zero humidity, for ions to be transfered upon contact. This article follows the review article by McCarty and Whitesides, Electrostatic Charging Due to Separation of Ions at Interfaces: Contact Electrification of Ionic Electrets, published in the chemistry journal Angewandte Chemie International Edition, in 2008. Whitesides is the most highly cited living chemist, and his research group investigates topics ranging from nanofabrication to the origins of life. Logan McCarty received his PhD as part of Whitesides group and performed some of the research that the review article reports on.