Sensor
The piezoelectric effect is the ability of certain crystalline materials to convert mechanical stress into electrical signals and vice versa. The industrially most important piezoelectric materials consist of ferroelectric polycrystalline ceramics. These piezoelectric materials possess a Perowskit crystalline structure.
Above a certain temperature, the so-called Curie temperature, these kinds of materials possess a cubic elementary cell with a centre of symmetry. The main areas of the positive and negative charges are found in the centre of the elementary cell of the crystal. The materials are paraelectric. There is no detectable piezoelectric effect.
