PIEZOELECTRICITY
- SCI & TECH
News:
Piezoelectricity: Why
quartz ticks
What's
in the news?
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Piezoelectricity is a remarkable
phenomenon whereby some materials – including quartz, ceramics such as lead
zirconate titanate (PZT), and even certain biological substances like bone
and the tendons – can generate an
electric charge in response to mechanical stress. This property is the
result of their unusual crystal structures.
Piezoelectricity:
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Piezoelectricity (also called the
piezoelectric effect) is the appearance of an electrical potential (a voltage, in other words) across the sides
of a crystal when you subject it to mechanical stress.
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In the reverse piezoelectric effect, a
crystal becomes mechanically stressed (deformed in shape) when a voltage is
applied across its opposite faces.
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Thus, Piezoelectric materials allow the conversion of energy from the mechanical
domain to the electrical domain and vice versa.
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It is due to the spontaneous separation of charge with certain crystal structures under
the right conditions.
Materials
exhibiting Piezoelectricity phenomenon:
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There are a wide variety of materials
which exhibit this phenomenon, including natural
quartz
crystals, semi-crystalline polyvinylidene polymer, polycrystalline
piezoceramic, bone and even wood.
Applications:
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They can be used to create various sensors
or actuators.
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Piezoelectric transducers are common in ultrasonic applications, such as
intrusion detectors and alarms.
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Piezoelectric devices are employed at AF
(audio frequencies) as pickups, microphones, earphones, beepers, and buzzers.
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In wireless applications, piezoelectricity
makes it possible to use crystals and ceramics as oscillators that generate
predictable and stable signals at RF (radio frequencies).