Piezo-electric effect

When some pressure or stress is applied to the surface of the piezo-electric crystal, the dimensions of the crystal change and an electric charge voltage will be developed across certain surfaces of the piezo-electric crystal. Conversely, when an electric charge voltage or potential is applied to the crystal, the crystal get deformed and hence, the dimensions of it will change. This effect is referred as piezo-electric effect.

  

All the piezo-electric transducers work on the principle of piezo-electric effect. The piezo-electric materials or the materials used in the construction of piezoelectric crystal are quartz, rochelle salt, dipotassium titrate, lithium sulphate, barium titanate, potassium dihydrogen phosphate, ammonium dihydrogen phosphate etc. A piezoelectric crystal subjected to force is illustrated in figure 6.1.