Dielectric and magnetic particles based metamaterials

• US 7,750,869 B2
• Filed: 07/24/2008
• Issued: 07/06/2010
• Est. Priority Date: 07/24/2007
• Status: Expired due to Fees

• Current Assignee: Northeastern University
• Original Assignee: Northeastern University
• Inventors: Mosallaei, Hossein
• Primary Examiner(s): Nguyen; Hoang V
• Application Number:
  US12/220,438
• Publication Number:
  US 20090040131A1
• Time in Patent Office: 712 Days
• Field of Search: 343/700.MS, 343/787, 343/911.R
• US Class Current: 343/911.00R
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: H01Q 15/0086 said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials

Abstract

RF-optical metamaterials with (±∈, ±μ) figures-of-merit of interest are constructed from coupled magnetic and dielectric multi-resonant multi-disks (finite-size cylinders) or multi-sphere lattices arranged in a periodic or a random fashion to offer tailored magnetic and electric dipole moments. The present metamaterials include embedded particles arrays that provide coupled magnetic and electronic modes equivalent to L (inductor) and C (capacitor) circuit models. Novel arrangements of these dipole modes (L and C) tailor the transfer function to the physics of interest.

Claims

1. A metamaterial array, comprising:

a matrix; and

a first set of particles embedded in the matrix, each particle in the first set being substantially identically shaped and having a substantially identical dielectric constant, the particles in the first set having a dielectric constant that is higher than the dielectric constant of the matrix, and the dielectric constant of the particles in the first set is less than about 120.

2. The metamaterial array of claim 1, further comprising:

a second set of particles embedded in the matrix, each particle in the second set being substantially identically shaped and having a substantially identical dielectric constant, the particles of the second set being different from the particles in the first set by at least one of the particle shape and the particle dielectric constant, the particles in the second set having a dielectric constant that is higher than the dielectric constant of the matrix and is less than about 120.

3. The metamaterial array of claim 2, wherein the two sets of particles form an interlocking lattice of particles embedded in the matrix.

4. The metamaterial array of claim 3, wherein the dielectric constants of the first and second particles are ˜

100.

5. The metamaterial array of claim 2, wherein the first set of particles provides electric resonance and the second set of particles provides magnetic resonance, and above the resonances the metamaterial is characterized by negative ∈

and negative μ

behavior.

6. The metamaterial array of claim 2, wherein the dielectric constants of the first and second particles are greater than about 40.

7. The metamaterial array of claim 2, wherein the dielectric constant of the matrix is ˜

1.

8. The metamaterial array of claim 2, wherein the particles comprise spheres.

9. The metamaterial array of claim 2, wherein the particles comprise disks or cubes.

10. The metamaterial array of claim 2, wherein the particles are closely coupled to increase the material frequency bandwidth.

11. The metamaterial array of claim 1, wherein array is configured so that the particles provide a magnetic resonance and the couplings between particles provide an electric resonance within substantially the same frequency band, and above the resonances the metamaterial is characterized as a backward wave medium with negative ∈

and negative μ

behaviors.

12. The metamaterial array of claim 11, wherein the dielectric constant of the first set of particles is ˜

12.5 and the dielectric constant of the matrix is ˜

1.

13. The metamaterial array of claim 11, wherein the first set of particles comprise gallium phosphide (GaP).

14. The metamaterial array of claim 1, wherein the first set of particles comprises hexaferrite, and the matrix comprises a low dielectric material.

15. The metamaterial array of claim 14, further comprising a dc magnetic bias that tunes the resonant frequency of the particles.

16. The metamaterial array of claim 1, wherein the matrix comprises a ferrite.

17. The metamaterial array of claim 16, wherein the first set of particles comprises a high-dielectric material, the ferrite matrix provides a negative permeability and the first set of particles provides an electric resonant mode, where above the resonance a negative effective permittivity is obtained.

18. The metamaterial array of claim 16, wherein the dielectric constant of the first set of particles is ˜

100.

19. The metamaterial array of claim 16, further comprising a dc magnetic bias that tunes the resonance of the ferrite matrix.

20. The metamaterial array of claim 1, wherein the first set of particles comprises a multiferroic material, and the matrix comprises a low dielectric material.

21. The metamaterial array of claim 20, further comprising a dc electric field bias that tunes the resonant frequency of the particles.

22. The metamaterial array of claim 1, wherein the matrix comprises a multiferroic material.

23. The metamaterial array of claim 22, wherein the first set of particles comprises a high-dielectric material, the multiferroic material matrix provides a negative permeability and the first set of particles provides an electric resonant mode, where above the resonance a negative effective permittivity is obtained.

24. The metamaterial array of claim 22, wherein the dielectric constant of the first set of particles is ˜

100.

25. The metamaterial array of claim 22, further comprising a dc electric field bias that tunes the resonance of the multiferroic material matrix.

26. The metamaterial array of claim 1, wherein the particles are closely coupled to increase the material frequency bandwidth.

27. The metamaterial array of claim 1, wherein the particles comprise spheres.

28. The metamaterial array of claim 1, wherein the particles comprise disks or cubes.

29. The metamaterial array of claim 1, wherein the array is isotropic.

30. The metamaterial array of claim 1, wherein the array comprises a three-dimensional (3D) array.

31. The metamaterial array of claim 1, wherein the array comprises a two-dimensional (2D) array.

32. The metamaterial array of claim 1, wherein the array provides negative refraction in an optical range.

33. The metamaterial array of claim 1, wherein the array provides negative refraction in a microwave range.

34. The metamaterial array of claim 1, wherein the array comprises a unit cell comprising multi-resonant particles to enhance the material frequency bandwidth.

35. The metamaterial array of claim 1, wherein the metamaterial array is characterized by an effective permittivity, an effective permeability and a resonance frequency, wherein at least one of the effective permittivity and the effective permeability has a positive value below the resonance frequency and a negative value above the resonance frequency.

36. A method of fabricating a metamaterial array, comprising:

providing a matrix; and

embedding a first set of particles in the matrix, each particle in the first set being substantially identically shaped and having a substantially identical dielectric constant, the particles in the first set having a dielectric constant that is higher than the dielectric constant of the matrix, and the dielectric constant of the particles in the first set is less than about 120.

37. The method of claim 36, further comprising:

embedding a second set of particles in the matrix, each particle in the second set being substantially identically shaped and having a substantially identical dielectric constant, the particles of the second set being different from the particles in the first set by at least one of the particle shape and the particle dielectric constant, the particles in the second set having a dielectric constant that is higher than the dielectric constant of the matrix and is less than about 120.

38. The method of claim 37, wherein the two sets of particles form an interlocking lattice of particles embedded in the matrix.

39. The method of claim 36, wherein the particles comprise spheres.

40. The method of claim 36, wherein the particles comprise disks or cubes.

41. The method of claim 36, wherein the particles comprise gallium phosphide (GaP).

42. The method of claim 36, wherein the particles comprise hexaferrite.

43. The method of claim 36, wherein the particles comprise a multiferroic material.

44. The method of claim 36, wherein the matrix comprises ferrite.

45. The method of claim 36, wherein the matrix comprises a multiferroic material.

46. The method of claim 36, wherein the array comprises a three-dimensional (3D) array.

47. The method of claim 36, wherein the array comprises a two-dimensional (2D) array.

48. The method of claim 36, further comprising performing a stereolithography process to fabricate the metamaterial array.

49. The method of claim 36, further comprising performing a two-photon lithography process to fabricate the metamaterial array.

50. The method of claim 49, further comprising:

modeling the design of a metamaterial as an RLC circuit to provide a desired characteristic;

determining material parameters for the array based on the RLC circuit model; and

fabricating the metamaterial array based on the determined material parameters.