The piezoelectric element used for converting mechanical movement into electric signals. The mechanical deformation generates charges and this charge appears as a voltage across the electrodes.
The voltage is given by
V= Q/C
where, V= e.m.f. across electrode
Q= charges
C= capacitance
Operating principle: When force or pressure is applied to the piezoelectric material like quartz crystal or barium titanate, then an emf is generated across the material or vice versa.
Applications
1. Piezoelectric transducers are used in high frequency accelerometer. 2. Piezoelectric materials are used in industrial cleansing apparatus. 3. It is used in under water detection system i.e. SONAR. 4. These are used in measurement of surface roughness in accelerometers and vibration picks ups. 5. It is used in ultrasonic flow meters, non-destructive test (NDT) equipments 6. Piezoelectric materials are used in ultrasonic transducers.