Piezoelectricity
Piezoelectricity, electricity generated by certain crystals and ceramics when they are deformed by mechanical pressure. The effect is reversible, that is, an electric current can produce deformation in these crystals and ceramics. Crystals showing the piezoelectric effect include quartz and Rochelle salt. The most commonly used piezoelectric ceramic is barium titanate.
The piezoelectric effect is particularly useful in converting mechanical strain into electrical impulses and converting electrical impulses into mechanical strain. Piezoelectric crystals and ceramics are used in phonograph cartridges, microphones, electronic oscillators, and measuring instrments.