Due to its small size, it is easy to handle.It is used in the ultrasonic generator.These are used in stabilizing electric oscillators.These materials are used in dynamic measurements.The equivalent circuit of the Piezo-electric transducer.Ĭharge generation is across C p and R p is the leakage resistance Applications.These are able to be formed into most desirable shape.This material has high output insensitivity to temperature and humidity.The piezo-electric material shows high stability.Modes of operation of the piezo-electric crystal This is so because deformation is the real reason for charge generation. Sometimes it is better to express the output voltage in terms of deflection inspite of force. G is the voltage sensitivity and its unit is Vm/NĬrystal voltage sensitivity is the ratio of electric field intensity to the pressure Now, due to this charge, we will have an output voltage : C p = capacitance between electrodes The thickness of the crystal changes on application of force : A = area of crystal in m 2īy substituting the value of “force” in the “charge equation”: : d = charge sensitivity of the crystal C/N The magnitude and polarity of charges generated at the surface of crystal are proportional to the magnitude and direction of the force applied. The Piezo-electric crystal is shown below: In a nutshell, a piezo-electric transducer changes mechanical motion into electrical signals because mechanical motion generates charges and this charge appears as a voltage. In originality, they do not have piezo-electric properties but proper polarizing treatment is used for the production of such properties. The nature of ceramic materials is polycrystalline and made up of barium titanate. Quartz and Rochelle salt belongs to the natural group. Quartz crystal shows unique property by generating the electrical voltage on applying mechanical stress to it. Some commonly used piezo-electric materials include Rochelle salts, ammonium dihydrogen phosphate, quartz, lithium sulphate etc. The elements that demonstrate piezo-electric qualities are called electro-resistive elements. if a varying potential is given at a proper axis, it will automatically variate the dimensions of the crystal which leads to deformation of the crystal. Due to this property, the potential appears across the surface of a crystal of piezo-electric material if the dimensions of crystals are changed. Piezo-electric materials possess the property of piezoelectricity.

The electric potential can be easily measured by voltage measuring devices. The higher the force, higher will be the voltage at the output. The voltage is given as: Piezo-electric EffectĪs we have discussed that these transducers operate on the principle of the piezoelectric effect and here the word piezo means stress or force.

Piezo effect