Piezo materials

Technology

Piezo materials have the property of developing an electric charge on their surface when mechanical stress is exerted on them. These materials are produced by Noliac Ceramics.

An applied electric field produces in these materials a linearly proportional strain. The electrical response to mechanical stimulation is called the direct piezoelectric effect and the mechanical response to electrical simulation is called the converse piezoelectric effect.

Soft and hard doped materials

The properties of the materials are specified according to the EN 50324 European Standard.

On an international basis, it is usual to divide piezo ceramics into two groups. The antonyms “soft” and “hard” doped piezoelectric ceramics refer to the ferroelectric properties, i.e. the mobility of the dipoles or domains and hence also to the polarization / depolarization behavior.

“Soft” doped piezo ceramics are characterized by a comparitively high domain mobility and a resulting “ferroelectrically soft” behavior, i.e. relatively easy polarization.

In contrast, ferroelectrically “hard” doped PZT materials can be subjected to high electrical and mechanical stresses. The stability of their properties destines them for high-power applications.