Charges build up due to exchange of material, study suggests
A balloon rubbed against the head can be both a hair-raising and a hair-tearing experience, a new study suggests. Clumps of balloon and hair invisible to the naked eye may break off each object during contact and stick to the other.
The existence of this exchange could challenge traditional theories about how static electricity builds up, a process known as contact electrification.
“The basic assumptions people have made about contact electrification are wrong,” says Bartosz Grzybowski, a physical chemist at Northwestern University in Evanston, Ill. He and his colleagues describe their new take on static electricity online June 23 in Science.
It’s long been known that some insulators — materials that don’t conduct electricity — build up charge when rubbed together. One object is usually assumed to pick up positive charges uniformly distributed across its surface, while the other picks up negative charges. Where