sciencehabit writes: That metal ball that makes your hair stand on end at science museums may have a powerful new use. Scientists have found a way to combine these Van de Graaff generators with a common laboratory instrument to detect drugs, explosives, and other illicit materials on the human body. In the laboratory, scientists had a volunteer touch a Van de Graaff generator for 2 seconds to charge his body to 400,000 volts. This ionized compounds on the surface of his body. The person then pointed their charged finger toward the inlet of a mass spectrometer, and ions from their body entered the machine. In various tests, the machine correctly identified explosives, flammable solvents, cocaine, and acetaminophen on the skin.