Electro-mechanical properties of different piezoelectric materials
Electro-mechanical properties of different piezoelectric materials are listed in Table 31.1. Here, Λ represents the free-strain in a piezo-electric actuator without any constraining force.
Table 31.1: Electro-mechanical properties of important piezoelectric materials
Property |
PZT (Hard) |
PZT(soft) |
PZT-PVDF |
PMN-PT |
LiNbO 3 |
PVDF |
d33 (pC/N) |
190 |
425 |
120 |
1240 |
6 |
30 |
d31 (pC/N) |
-55 |
-170 |
- |
- |
-0.85 |
-16 |
g33 mV-m/N |
54 |
27 |
300 |
43 |
|
150 |
g31 mV-m/N |
-16 |
-11 |
- |
- |
|
-150 |
k33 |
0.67 |
0.70 |
0.80 |
0.92 |
0.17 |
0.11 |
Ep (GPa) |
63 |
45 |
~ 30 |
100 |
20 |
2.7 |
Density(ρ) (Kg/m3) |
7500 |
7500 |
3300 |
8120 |
4600 |
1760 |
Λ |
1500 |
1980 |
400 |
3100 |
1210 |
700 |
Table 31.1 reveals that the composite of PZT-PVDF has high electro-mechanical coupling with a moderate density which is in between those of PZT and PVDF. The elastic modulus is also seen to be quite high in comparison with that of PVDF. Thus, such composites present a good trade-off between excellent actuation potential of PZT and sensing capability of PVDF. Often, the high-actuation strain generating capability of Shape Memory Alloy is exploited by doping elements of SMA into piezo-ceramic material. The product is known as shape memory ceramic active material. As high as 6000 m -strain along with memory effect is achieved through this material. However, such materials are still in the developmental stage, hence their commercial/engineering viability is yet to be established.
Congratulations! You have finished Lecture 31. |
