What is the piezoelectric effect, and as used

What associations you are having a piezoelectric element with the word? Lighter or electric ignition. In fact, the piezoelectric effect is used in much larger areas. In this article I will tell you that all is piezoelectric and where it is actively used. So, let's begin.

History of discovery

This effect was discovered in 1880 by the Curie brothers. As a result of experiments conducted it was established that the electric charges formed during compression or stretching of individual crystals of natural origin on their faces.

Outdoor effect scientists have named "piezoelectricity" (from the Greek «piezo» literally - "push"), and the crystals which have such properties, became known as piezoelectric.

As public works crystals this effect

As it turned by this effect are endowed with crystals of both natural origin (tourmaline, quartz, etc.) and cultured. And the list of such crystals is replenished with an enviable constancy.

If such a crystal to begin to compress or stretch to a certain plane, is formed on the faces of the electrical charge with a small potential difference.

If, however, on these faces to connect the conductors, at the time of compression or stretching of a small electrical pulse will pass through them. This is a manifestation of the piezoelectric effect. If we have a constant pressure, then no electric impulse formation is not observed.

Thus such crystals have easy excellent elasticity. If you remove the distorting effects, the crystal returns to its original position without any inertial oscillations.

If the crystal is already under pressure to make more efforts or to remove it altogether, it immediately reacts by an electric pulse.

Truth at the opening of the effect of the current strength of the oscillating crystal was negligible and that was the main obstacle in the active use of the opening practice. But with the advent of modern technology when the current can be enhanced by hundreds of times, the problem has been eliminated, and piezoelectric cells were actively used.

Note. At the moment, already open elements, the piezoelectric effect which manifests itself in strongly enough.

Where and how to use piezoelectric

These crystals were used extensively in the steel ultrasonic flaw detection (detection of defects in a variety of metal articles).

The electromechanical converters for stabilizing the frequency in the multichannel communication filters, pressure sensors in various fixation and amplification, adapters, and so on. N. In fact, the list of which piezo elements are used in varying degrees, is very long.

The main features of piezo crystals

Reverse effect piezoelectric crystals

But much more important was the discovery of the so-called rebound effect, which concluded as follows:

If the corresponding faces of the crystal to exert a certain charge, the crystal itself will undergo deformation.

That is, if the crystal lodge electrical oscillations corresponding to the sound frequency, crystal, hesitate, will broadcast the sound waves in the environment. In other words, a single crystal can be both a speaker and a microphone at the same time.

The natural frequency of mechanical oscillations

Just in these crystals has its own mechanical frequency, and if a crystal file a charge with the frequency that coincides with its own, then it will go into resonance, will start to fluctuate particularly strongly. This principle is used in piezoelectric stabilizers that maintain a constant frequency oscillators undamped oscillations.

The same effect is true for enclosed mechanical vibrations. Due to this acoustic devices have been created, which is isolated from the variety of sounds coming only those that are necessary for any purpose.

manufacture of piezoelectric elements

In order to use the piezoelectric effect it is not necessary to use a crystal. Suffice it sawed into plates, the cut must be strictly oriented crystallographic axes. And then from the blanks to form rectangular or circular plate.

In this case also the plate thickness is strictly observed, because it affects the resonance frequency. Further, these plates (one or several) are joined with metal plates and thereby to obtain a piezoelectric element.

conclusion

As you can see a piezoelectric element is used in much larger areas than it seemed at first glance. If you liked this article, you will appreciate her huskies and thank you for your attention!