Piezolelectricity

[Elshan Aliyev]

Piezoelectricity is the ability of certain materials to generate the charges on surface of itself under application of stress.

 

Lets take the quartz sample. Apply force to it, make it compress. According to piezoelectric effect minus and plus charges will generate over the opposite surfaces of crystal. Thus we can measure the voltage between these charges in an open circuit. We can make several thousand of volts via corresponding high compressional force.

 

My question is related to closed circuit. If we take quartz sample and apply stress to it in closed circuit then what would happen???

 

It is obvious that the current will flow through the circuit and voltage will disappear. However, might there be any small quantity of stress that the voltage generated by this action would not be enough to make current flux??

 

I was wondering might there be any saturation value of stress and voltage that the current flux does not take place until this value is reached…..

 

Many thanks,

Elshan

 

 

[swansont]

One possible result is that the quartz crystal will oscillate, as the voltage it creates and the one that it sees from the circuit are out of phase (it takes time for the circuit to respond). That's the starting point for a clock.

[Enthalpy]

There is no threshold at all: the response is linear, that's why piezo materials make extremely sensitive sensors of force, pressure, acceleration... Quartz is less efficient than other materials but serves sometimes as a precise reference.

 

Piezo materials also serve to make electric frequency filters (and oscillators); I used one at -124dBm or 4*10^-16 W and it worked as expected - this tells there is no threshold on tiny signals and forces and deformation.

 

The linear response enables a tensor to represent it.

 

The free flow of current in a short circuit means no voltage stands. The resulting movement of charge changes the mechanical behaviour of the piezo material - a bit with quartz which is NOT commonly used, a lot with PVDF.