Piezoelectric effect

The piezoelectric effect consists in the development of unlike electric charges on the faces of certain crystals when they are mechanically distorted in specific directions. This effect is observed in quartz, tourmaline, barium titanate and sphalerite. In quartz, the piezoelectric effect takes place along the electrical axes. If the direction of deformation is reversed, the chargers developed on the surfaces will also be reversed. The inverse piezoelectric effect consists in changing the linear dimensions of certain crystals by applying an electric field.