The triboelectricity is a contact electrification which results from frictional contact of two different materials. This effect is used for electric charge generation in a Van de Graaff Generator, which uses a moving belt on two rollers to accumulate very high electrostatically stable voltages on a hollow metal globe on the top of the stand. Invented in 1929 by American physicist Robert J. Van de Graaff, it was adapted for use as a particle accelerator. The generator became an important research tool for atomic physicists and was also used to produce high-energy x-rays helpful in treating cancer. This undergraduate level setup demonstrates useful aspects of static electricity such as:
- charge is stored on surfaces
- electric field increases at sharp edges
- Field in the interior of a metallic shell is zero.