piezoelectric effect
In piezoceramics and in certain crystals, for example tourmalines, quartz and Seignette salts, electrical charges are formed on the surface when pressure is applied. This phenomenon is referred to by the Greek word for pressure: Piezo.
The piezo effect states that charges are generated when a piezoceramic or quartz crystal is deformed. Such deformations can be caused by mechanical stresses, by pressure, tension or torsion. The effect was discovered in the late 19th century by the Jacques and Pierre Curie brothers and can also be reversed as an inverse piezoelectric effect by applying a voltage to a crystal to bend it. The polycrystalline crystal structures used for the piezoelectric effect are grown and cut in the direction of a specific crystal structure.
The normal and inverse piezoelectric effect is used in sensors, microphones, piezo loudspeakers, piezo printers, piezo motors, VL switches, surface acoustic wave filters and in consumer electronics such as lighters, as sound generators in wristwatches, alarm clocks or computers and in pickups of record players.