Polymer-based piezoelectric composite material and piezoelectric film
Provided are a polymer-based piezoelectric composite material and a piezoelectric film having piezoelectric conversion characteristics stabilized by suppressing a change in piezoelectric conversion efficiency in various humidity environments. The polymer-based piezoelectric composite material is a polymer-based piezoelectric composite material including piezoelectric particles in a matrix containing a polymer material, in which a pore volume per unit area is in a range of 0.01 μL/mm 2 to 1.7 μL/mm 2 , which is acquired in a manner that a mercury penetration amount of a sample obtained by cutting a polymer-based piezoelectric composite material in a thickness direction and cutting out the polymer-based piezoelectric particle into a size of 12.5 mm×25 mm is measured by a mercury penetration method, and the penetration amount is divided by an area of a cross-section of the sample.
1. A polymer-based piezoelectric composite material comprising:
piezoelectric particles in a matrix containing a polymer material,
wherein a pore volume per unit area is in a range of 0.01 μL/mm 2 to 1.7 μL/mm 2 , which is acquired in a manner that an electrode layer is formed on each of both surfaces of the polymer-based piezoelectric composite material to form a piezoelectric film and a mercury penetration amount of a sample obtained by cutting the piezoelectric film in a thickness direction and cutting out the piezoelectric film into a size of 12.5 mm×25 mm is measured by a mercury penetration method, and the penetration amount is divided by an area of a cross section of the sample.
2. The polymer-based piezoelectric composite material according to claim 1 ,
wherein the polymer-based piezoelectric composite material is polarized in the thickness direction.
3. The polymer-based piezoelectric composite material according to claim 2 ,
wherein piezoelectric characteristics do not include in-plane anisotropy.
4. The polymer-based piezoelectric composite material according to claim 2 ,
wherein the polymer material has a viscoelasticity at room temperature.
5. The polymer-based piezoelectric composite material according to claim 1 ,
wherein piezoelectric characteristics do not include in-plane anisotropy.
6. The polymer-based piezoelectric composite material according to claim 5 ,
wherein the polymer material has a viscoelasticity at room temperature.
7. The polymer-based piezoelectric composite material according to claim 1 ,
wherein the polymer material has a viscoelasticity at room temperature.
8. A piezoelectric film comprising:
a polymer-based piezoelectric composite material which contains piezoelectric particles in a matrix containing a polymer material; and
an electrode layer which is formed on each of both surfaces of the polymer-based piezoelectric composite material,
wherein a pore volume per unit area is in a range of 0.01 μL/mm 2 to 1.7 μL/mm 2 , which is acquired in a manner that a mercury penetration amount of a sample obtained by cutting the piezoelectric film in a thickness direction and cutting out the piezoelectric film into a size of 12.5 mm×25 mm is measured by a mercury penetration method, and the penetration amount is divided by an area of a cross-section of the polymer-based piezoelectric composite material of the sample.
9. The piezoelectric film according to claim 8 , further comprising:
a protective layer laminated on a surface of the electrode layer opposite to a surface on the polymer-based piezoelectric composite material side.
10. The piezoelectric film according to claim 9 ,
wherein the polymer-based piezoelectric composite material is polarized in the thickness direction.
11. The piezoelectric film according to claim 9 ,
wherein piezoelectric characteristics do not include in-plane anisotropy.
12. The piezoelectric film according to claim 9 ,
wherein the polymer material has a viscoelasticity at room temperature.
13. The piezoelectric film according to claim 8 ,
wherein the polymer-based piezoelectric composite material is polarized in the thickness direction.
14. The piezoelectric film according to claim 13 ,
wherein piezoelectric characteristics do not include in-plane anisotropy.
15. The piezoelectric film according to claim 13 ,
wherein the polymer material has a viscoelasticity at room temperature.
16. The piezoelectric film according to claim 8 ,
wherein piezoelectric characteristics do not include in-plane anisotropy.
17. The piezoelectric film according to claim 16 ,
wherein the polymer material has a viscoelasticity at room temperature.
18. The piezoelectric film according to claim 8 ,
wherein the polymer material has a viscoelasticity at room temperature.