pietsosähköisyys

Piezoelectricity is a phenomenon observed in certain crystalline materials where mechanical stress induces an electric charge, and conversely, an applied electric field causes a deformation of the material. The name "piezoelectricity" originates from the Greek word "piezein," meaning to squeeze or press.

This effect is not found in all materials. It is a property of crystals that lack a center of symmetry in their atomic structure. When these materials are subjected to mechanical pressure, their internal electric dipoles align in such a way that a net electric polarization occurs, resulting in a voltage across the material. The magnitude of this voltage is directly proportional to the applied stress.

The inverse piezoelectric effect is equally important. Applying an electric field across a piezoelectric material causes a change in its shape. This deformation is also proportional to the applied electric field. This inverse effect is widely used in various actuators and precision positioning systems.

Piezoelectric materials have found numerous applications in modern technology. They are used in sensors, such as pressure sensors and accelerometers, where the mechanical input is converted into an electrical signal. They are also employed in actuators, like in inkjet printers and ultrasonic transducers for medical imaging and sonar. Furthermore, piezoelectric crystals are utilized in lighters as spark generators, in quartz watches for timekeeping due to their precise oscillation frequency, and in microphones and loudspeakers. The development of new piezoelectric materials with enhanced properties continues to expand their technological relevance.