Electrophorus

[1][2][3][4] Italian scientist Alessandro Volta improved and popularized the device in 1775,[5] and is sometimes erroneously credited with its invention.

[6][7] The word electrophorus was coined by Volta from the Greek ήλεκτρον, elektron, and φορεύς, phoreus, meaning 'electricity bearer'.

The dielectric does not transfer a significant fraction of its surface charge to the metal because the microscopic contact is poor.

One of the largest examples of an electrophorus was built in 1777 by German scientist Georg Christoph Lichtenberg.

This separation takes work since the lowest energy state implies uncharged objects.