Piezoelectrics are materials that change their shape when an electric field is applied, with wide-ranging applications including printing ink onto paper and precisely moving the tip of a scanning tunnelling microscope. Currently, the most effective piezoelectrics are those in single crystal form, because they have a large electrostrain value (> 1 percent), which is a mark of how much the material can change its shape when the electric field is applied. However, they are very expensive and difficult to manufacture. Ceramic piezoelectrics, made up of multiple tiny crystals, are at least a hundred times cheaper and easy to mass-produce, but they usually have very low electrostrain values.