Piezoelectric Crystals

1
Piezoelectric Crystals

• MEEN 3344
• By Matthew Kelso

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Piezoelectric Crystals

• Crystals that generate a voltage when a stress is
  applied to them.
• The inverse effect is also true a voltage
  causes deformation.
• This is due to complicated crystal structure that
  is unsymmetrical about the center.

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How It Works

• In these crystals, the positive and negative
  charges are separated, but symmetrical.
• When a stress is applied, the symmetry is
  disrupted and there is an uneven charge
  distribution.
• This uneven distribution generates a voltage
  across the system.

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Types of Crystals

• Quartz is the most commonly used crystal.
• Natural Crystals Quartz, Rochelle Salt, Topaz,
  Cane Sugar, Bone
• Some ceramics
• Polyvinylidene Fluoride (PVDF)

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Applications

• Vibration Dampeners
• Energy farm
• Quartz Watches
• Guitar Pickups
• Lighters
• Sonar
• Phonographs
• Printers

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References

• http//www.piezo.com/tech4history.html
• http//en.wikipedia.org/wiki/Piezoelectricity
• http//openlearn.open.ac.uk/mod/resource/view.php?
  id257278
• Callister, W.D., Fundamentals of Materials
  Science and Engineering An Integrated Approach,
  3rd ed. Wiley and Sons, 2008, Online
• http//www.treehugger.com/files/2006/08/japan_tick
  et_gates.php
• http//www.answers.com/topic/piezoelectricity
• http//www.slashgear.com/gibson-powertune-the-guit
  ar-that-tunes-itself-047793/
• http//gemscollection.blogspot.com/2007/08/topaz-g
  emstone.html
• http//www.handsofhopedisasterreliefservices.org/b
  2b/confectionery_and_candy/1/
• http//flickr.com/photos/14833125_at_N02/2182032919
• http//www.mineralminers.com/images/phantom-quartz
  /polx/phqp271.jpg
• http//www.filterforge.com/filters/4802.html
• http//www.phonodoc.com/phono.htm
• http//www.global-b2b-network.com/b2b/26/37/858/15
  7887/piezo_igniters.html
• http//en.wikipedia.org/wiki/Inkjet_printer
• http//www.explainthatstuff.com/insidequartzwatch.
  jpg