1 Piezoelectricity GLY 4200 – Lecture 3 –Fall, 2012

2 Pierre and Jacques Curie Pierre and Jacques Curie discovered piezoelectricity in 1881

3 Piezoelectric Effect Diagram

4 Illustration of Piezoelectric Effect Generation of current by compression

5 Lighting a Neon Bulb Demonstration of piezoelectricity

6 Ion Generation Cellophane is wrapped around nylon strings and pulled down The strings repel each other A gun, containing a piezoelectric crystal, is aimed at the string Pulling the trigger causes the gun to emit positive ions Negative ions are emitted when the trigger is released When the trigger is released, the strings relax

7 Polarization P i = d ijk σ jk where  P i is the polarization vector,  d ijk is the piezoelectric modulus, and  σ jk is the stress tensor