Triboelectric Effect

The triboelectric effect is the transfer of electric charge between two objects when they touch or rub against each other, an effect found to some degree in nearly every solid material and also between solids, liquids and gases. When the surfaces separate they retain opposite charges, and the amount of charge transferred depends on factors such as the difference in the materials own work functions, surface strain, humidity and the surfaces condition at the nanoscale, with the everyday buildup of static electricity being one common result. The same charge generating contact and separation is put to deliberate use in triboelectric nanogenerators, devices that convert small amounts of mechanical energy such as touch or vibration into usable electricity. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/