Piezoelectric Effect: Part 2 of 2

A piezoelectric crystal is pressed producing an electric current that lights an attached bulb. While still pressed the electric circuit is broken. Once the circuit is restored and electricity allowed to flow, the stress in the crystal is relieved.

In order to properly present the sound and the flash of the piezoelectric device these movies are provided at 30 frames per second. Insufficient network bandwidth and other variables may result in dropped frames. If you do not see the flash when you hear the sound, you might replay the movie or use the scrub control to locate the flash.

Discussion: 

When pressure is applied to a piezoelectric material such as quartz (SiO2), the crystal deforms in such a way as to create an electric dipole moment, generating an electric current. Releasing pressure will also produce a current. Piezoelectric crystals are used in the strikers of lighters to generate a spark.

The complementary effect is also observed. When a voltage is applied across a piezoelectric material, the crystal deforms.

Credits: 
  • Design and Demonstration
    • George Lisensky Beloit College, Beloit, WI 53511
  • Text
    • George Lisensky Beloit College, Beloit, WI 53511
    • Nancy S. Gettys University of Wisconsin - Madison, Madison, WI 53706
    • David Phillips Wabash College, Crawfordsville, IN 47933
  • Video
    • Jerrold J. Jacobsen University of Wisconsin - Madison, Madison, WI 53706