Page 237 - Mechanics of Microelectromechanical Systems
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224 Chapter 4
Figure 4.40 Poling of a piezoelectric material by means of an external electric field
It should be mentioned that below a critical temperature, called the Curie
point (in honor of Jacques and Pierre Curie who discovered the piezoelectric
phenomenon in 1880), a piezoelectric material has a tetragonal symmetry
with the dipoles arranged such that the positive and negative poles are not
coincident.
Figure 4.41 Piezoelectric transaction: (a) sensing through the direct piezoelectric effect;
(b) actuation through the reversed piezoelectric effect
