Flexible Piezoelectric Material, Production and Use Thereof

• US 20150200351A1
• Filed: 01/13/2014
• Published: 07/16/2015
• Est. Priority Date: 01/13/2014
• Status: Active Grant

• Current Assignee: Meggitt A/S (CTS Corporation)
• Original Assignee: Meggitt A/S (CTS Corporation)
• Inventors: ZAWADA, Tomasz, HANSEN, Karsten, ASTAFIEV, Konstantin, RINGGAARD, Erling
• Granted Patent: US 10,079,336 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H10N 30/074 by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing
• CPC Class Codes: H10N 30/092 Forming composite materials
• CPC Class Codes: H10N 30/852 Composite materials, e.g. having 1-3 or 2-2 type connectivity

Abstract

A composite piezoelectric material, manufacturing of the composite material and use of this composite material in piezoelectric components are disclosed. More particularly, a piezoelectric thick film materials or piezoelectric paint being a composite piezoelectric material including piezoelectric particles randomly dispersed within a polymer matrix are disclosed. A paste of composite piezoelectric material including a matrix of polymer having a relative permittivity≧3, normally ≧6, sintered piezoelectric particles having a relative permittivity in the range of 100-5000, normally in the range of 400-1000 and an average particle size between 1 and 50 μm, although the particles should be smaller than 1/10 of the final thickness of the final layer of piezoelectric material, and additives such as dispersing agents or thinner are disclosed where the final paste has a 0-3 connectivity pattern, a content of sintered piezoelectric particles between 15 and 75 vol %, normally between 40 and 60 vol %.

Claims

1. A paste of composite piezoelectric material comprising:

a matrix of polymer having a relative permittivity≧

3, normally ≧

6,

sintered piezoelectric particles having a relative permittivity in the range of 100-5000, and an average particle size between 1 and 50 μ

m, although the particles should be smaller than 1/10 of the final thickness of the final layer of piezoelectric material, and

additives comprising dispersing agents or thinner,

Wherein the final paste comprises;

a 0-3 connectivity pattern,

a content of sintered piezoelectric particles between 15 and 75 vol %.

2. The paste according to claim 1, wherein the sintered piezoelectric particles are manufactured from a ceramic piezoelectric active powder which is first pressed and then sintered at a temperature above 1100°

C. for a period of at least 0.5 hours.

3. The paste according to claim 2, wherein the sintered piezoelectric material has been subjected to crushing and milling to obtain a desired particle size of d_0.5=1-50 μ

m.

4. The paste according to claim 1, wherein the cured polymer matrix is flexible having a Young'"'"'s Modulus E≦

10 GPa.

5. The paste according to claim 1, wherein the viscosity of the paste is 5-15 Pa·

s at a shear rate equal to 33.3 (1/sec) and satisfying wetting properties between the paste and substrate are obtained.

6. The paste according to claim 1, wherein the binding matrix comprises or consists of a fluoride based polymer.

7. The paste according to claim 1, wherein the sintered piezoelectric particles comprise a PZT material.

8. The paste according to claim 1, wherein the thickness of the final layer of piezoelectric material is ≧

10 μ

m.

9. The paste according to claim 1, wherein the sintered piezoelectric particles have a relative permittivity in range of 400-1000.

10. The paste according to claim 1, wherein then final paste comprises a content of sintered piezoelectric particles between normally between 40 and 60 vol %.

11. The paste according to claim 2, wherein the ceramic piezoelectric active powder sintered at a temperature between 1100-1300°

for 1-2 hours.

12. The paste according to claim 2, wherein the sintered piezoelectric material has been subjected to crushing and milling to obtain a desired particle size of d_0.5=7-15 μ

m.

13. The paste according to claim 1, wherein the cured polymer matrix is flexible having a Young'"'"'s Modulus E≦

4 GPa.

16. A method of manufacturing a piezoelectric component, the method comprising:

depositing a layer of a paste of piezoelectric material according to claim 1 on a substrate, the layer being thicker than 10 μ

m, the final layer on the substrate optionally formed by depositing more than one layer of paste and each layer or combination of layers are created in the final functional thickness and shape by deposition, and

curing the deposited layer of composite piezoelectric material.

17. A method of manufacturing a piezoelectric component according to claim 16, wherein the curing comprises heating the deposited layer on the substrate at a temperature below 300°

C.

18. A method of manufacturing a piezoelectric component according to claims 16, wherein the layer(s) of fluid composite piezoelectric material is deposited by screen-printing or pad-printing.

19. A method of manufacturing a piezoelectric component according to claim 11, wherein the substrate is a woven or non-woven textile, paper, polymer or composite material or a curved or non-curved surface.

20. A method of manufacturing a piezoelectric component according to claim 11, wherein the component is used for detecting physical changes in the substrate, or the component is used for energy harvesting.

14. A method of preparing a composite piezoelectric material comprising:

1) preparing sintered piezoelectric particles having a relative permittivity in the range of 100-5000 and a average particle size between 1 and 50 μ

m, although the particles should be smaller than 1/10 of the final thickness of the final layer of piezoelectric material,

2) mixing between 15 and 75 vol % of sintered piezoelectric particles with 60-40 wt % of a polymer matrix having a relative permittivity ≧

3, and an additive; and

3) agitating the obtained mixture until a homogenous paste having a desired viscosity and satisfying wetting properties between paste and substrate is obtained.

15. The method of preparing a composite piezoelectric material according to claim 14 wherein the agitation is performed in a roller mill.