The Piezoelectric effect of natural crystals was discovered by the Curie brothers in 1880. At the time Rochelle salts and tourmaline were the best known Piezoelectric materials. The ferroelectric ceramics, developed in the 30's for the production of electrical capacitors, also showed Piezoelectric properties. The concentrated research and materials development led to the present highly-effective Piezoelectric materials, whose materials parameters can be varied in a wide range and can therefore be optimally adapted to the customers requirements. If a force is applied to a Piezoelectric structure, surface charges are induced by the dielectric displacement, and therefore an electric field is built up.
Electrodes transforms it into electric voltage.
If the electrodes are shorted, the surface charges balance out by a current. When an electric field acts on a Piezoelectric structure it becomes distorted. If this distortion is prevented, a T elastic tension occurs. A force F is therefore applied to the device which prevents the distortion of the Piezoelectric body. This reversal of the direct Piezoelectric effect is defined as indirect or inverse Piezo effect.