Energy harvesting using a thermoelectric material

• US 7,397,169 B2
• Filed: 03/16/2005
• Issued: 07/08/2008
• Est. Priority Date: 03/19/2004
• Status: Expired due to Fees

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Inventors: Radousky, Harry B., Nersessian, Nersesse, Carman, Gregory P.
• Primary Examiner(s): Dougherty; Thomas M
• Application Number:
  US11/082,632
• Publication Number:
  US 20050205125A1
• Time in Patent Office: 1,210 Days
• Field of Search: 310/339
• US Class Current: 310/339
• CPC Class Codes: H02N 2/18 producing electrical output from mechanical input, e.g. generators for measurement devices G01
• CPC Class Codes: H10N 30/306 Cantilevers

Abstract

A novel energy harvesting system and method utilizing a thermoelectric having a material exhibiting a large thermally induced strain (TIS) due to a phase transformation and a material exhibiting a stress induced electric field is introduced. A material that exhibits such a phase transformation exhibits a large increase in the coefficient of thermal expansion over an incremental temperature range (typically several degrees Kelvin). When such a material is arranged in a geometric configuration, such as, for a example, a laminate with a material that exhibits a stress induced electric field (e.g. a piezoelectric material) the thermally induced strain is converted to an electric field.

Claims

1. An energy harvesting system, comprising:

a cooling source capable of producing a predetermined temperature gradient;

a heating source capable of producing a predetermined temperature gradient;

a thermoelectric material, further comprising;

one or more thermostrictive materials capable of producing a predetermined induced strain when subjected to a cycled contact with said cooling source and said heating source over a predetermined temperature range;

one or more piezoelectric materials capable of producing an induced voltage resulting from said predetermined induced strain produced by said one or more thermostrictive materials; and

wherein a predetermined power output is capable of being produced by said system at a frequency determined by said cycled predetermined temperature range.

2. The system of claim 1, wherein said one or more thermostrictive materials comprises at least one of:

Gd₅Ge₂Si₂;

La(Fe_0.88Si_0.12)₁₃;

La_0.7Ba_0.3MnO₃;

FeRh;

[(Fe_1-x,Ni_x)₄₉Rh₅₁], with x in the range between about 0.000 and about 0.050; and

Sm_0.55Sr_0.45MnO₃;

[MnFeP_1-xAs_x], with x in the range between about 0.250 and about 0.065;

NiTi;

NiTiCu;

NiTiPd;

AuCd;

CuZnAl; and

Ni₂MnGaLa.

3. The system of claim 1, wherein said one or more piezoelectric materials comprises at least one lead zirconate titanate (PZT) material selected from:

PZT-5H, PZT-5A, PZT-4, and PZT-8.

4. The system of claim 3, wherein said one or more piezoelectric materials comprises at least one material selected from:

a piezoelectric polymer and a piezoelectric single crystal.

5. The system of claim 4, wherein said piezoelectric material comprises a Seeback coefficient of up to about 1800 volts/°

K.

6. The system of claim 1, wherein said predetermined temperature range comprises at least 20°

C.

7. The system of claim 1, wherein said strain can be up to about 10%.

8. The system of claim 6, wherein said predetermined temperature range comprises computer generated heat.

9. The system of claim 6, wherein said predetermined temperature range comprises heat produced from hot asphalt.

10. The system of claim 6, wherein said predetermined temperature range comprises solar energy.

11. The system of claim 1, wherein said thermoelectric material comprises a laminate of said one or more thermostrictive materials and said one or more piezoelectric materials.

12. The system of claim 1, wherein said one or more thermostrictive materials comprises at least one of:

single crystals, polycrystalline, and composites.

13. The system of claim 1, wherein said cycled contact comprises a frequency of up to about 1 kHz.

14. The system of claim 1, wherein said cycled contact comprises a frequency of greater than about 1 kHz.

15. An energy harvesting method, comprising:

providing a cooling source capable of producing a predetermined temperature gradient;

providing a heating source capable of producing a predetermined temperature gradient;

providing a thermoelectric material, wherein said thermoelectric material further comprises;

one or more thermostrictive materials capable of producing a predetermined induced strain when subjected to a cycled contact with said cooling source and said heating source over a predetermined temperature range;

one or more piezoelectric materials capable of producing an induced voltage resulting from said predetermined induced strain produced by said one or more thermostrictive materials; and

wherein a predetermined power output is capable of being produced at a frequency determined by said cycled predetermined temperature range.

16. The method of claim 15, wherein said one or more thermostrictive materials comprises at least one of:

Gd₅Ge₂Si₂;

La(Fe_0.88Si_0.12)₁₃;

La_0.7Ba_0.3MnO₃;

FeRh;

[(Fe_1-xNi_x)₄₉Rh₅₁], with x in the range between about 0.000 and about 0.050; and

Sm_0.55Sr_0.45MnO₃;

[MnFeP_1-xAs_x], with x in the range between about 0.250 and about 0.065;

NiTi;

NiTiCu;

NiTiPd;

AuCd;

CuZnAl; and

Ni₂MnGaLa.

17. The method of claim 15, wherein said one or more piezoelectric materials comprises at least one lead zirconate titanate (PZT) material selected from:

PZT-5H, PZT-5A, PZT-4, and PZT-8.

18. The method of claim 17, wherein said one or more piezoelectric materials comprises at least one material selected from:

a piezoelectric polymer and a piezoelectric single crystal.

19. The method of claim 18, wherein said piezoelectric material comprises a Seeback coefficient of up to about 1800 volts/°

K.

20. The method of claim 15, wherein said predetermined temperature range comprises at least 20°

C.

21. The method of claim 15, wherein said strain can be up to about 10%.

22. The method of claim 20, wherein said predetermined temperature range comprises computer generated heat.

23. The method of claim 20, wherein said predetermined temperature range comprises heat produced from hot asphalt.

24. The method of claim 20, wherein said predetermined temperature range comprises solar energy.

25. The method of claim 15, wherein said thermoelectric material comprises a laminate of said one or more thermostrictive materials and said one or more piezoelectric materials.

26. The method of claim 15, wherein said one or more thermostrictive materials comprises single crystals.

27. The method of claim 15, wherein said cycled contact comprises a frequency of up to about 1 kHz.

28. The method of claim 15, wherein said cycled contact comprises a frequency of greater than about 1 kHz.