System for converting electromagnetic radiation to electrical energy using metamaterials

• US 10,374,524 B2
• Filed: 06/19/2015
• Issued: 08/06/2019
• Est. Priority Date: 06/20/2014
• Status: Active Grant

• Current Assignee: RedWave Energy, Inc.
• Original Assignee: RedWave Energy, Inc.
• Inventors: Brady, Patrick K, Kotter, Dale K., Park, Wounjhang
• Primary Examiner(s): Barrera, Ramon M
• Application Number:
  US14/745,299
• Publication Number:
  US 20150372621A1
• Time in Patent Office: 1,509 Days
• CPC Class Codes: G02B 1/002 made of materials engineered to provide properties not available in nature, e.g. metamaterials
• CPC Class Codes: H01L 31/00 Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof H10K30/00 takes precedence; devices consisting of a plurality of solid state components formed in, or on, a common substrate, other than combinations of radiation-sensitive components with one or more electric light sources, H01L27/00
• CPC Class Codes: H01L 31/0264 Inorganic materials
• CPC Class Codes: H01L 31/04 adapted as photovoltaic [PV] conversion devices testing thereof during manufacture H01L22/00; testing thereof after manufacture H02S50/10
• CPC Class Codes: H01Q 1/248 provided with an AC/DC converting device, e.g. rectennas
• CPC Class Codes: H02N 11/002 Generators
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

Spectral tuning of heat source to emit radiation at a desired frequency or frequency band is accomplished using metamaterials. The metamaterials include a structured geometry having holes with dimensions and spacing chosen such that the resulting surface will emit radiation in the desired spectrum. A collector can be made of a similar metamaterial or antenna array to detect the emitted radiation and transfer it to a converter device that converts the detected radiation to electricity. Embodiments also provide efficient coupling to the converter device for energy harvesting. Cooling of the converter devices can be accomplished using a cooling sink or deep space.

Claims

1. A system to convert heat into electricity, comprising:

a metamaterial having a surface that is tuned to generate an enhanced electric field at a desired frequency; and

a rectenna placed over the enhanced electric field, at a distance to interact with the generated electric field, and to produce electricity from the generated electric field.

2. The system of claim 1, wherein the surface of the metamaterial comprises a plurality of holes with dimensions and spacing to cause the surface to generate the enhanced electric field at the desired frequency, and wherein a rectenna is placed over each hole.

3. The system recited in claim 2, wherein each rectenna is placed in the near field over the holes at less than 0.5 wavelengths of the desired frequency.

4. The system recited in claim 1, wherein the rectenna comprises:

an antenna tuned to the desired frequency to interact with the generated electric field to generate an electric current in an antenna element; and

a transfer structure to convert the electric current into direct current.

5. The system recited in claim 1, further comprising at least one lead to carry the direct current to power another device or to an electricity storage device.

6. The system recited in claim 1, further comprising a cold source to act as a cold sink to cool the rectenna.

7. The system recited in claim 1, further comprising a thermally insulating and radiation transparent material placed between the surface of the metamaterial and the rectenna.

8. The system recited in claim 7, wherein the rectenna comprises an antenna element, further comprising a thermally conductive material to couple the antenna element to a cold source.

9. The system recited in claim 8, further comprising a thermally insulating material on either side of the thermally conductive material to prevent heat loss from a heat source.

10. The system recited in claim 2, wherein the hole dimensions and spacing form a periodic pattern on the surface of the metamaterial.

11. The system of claim 1, wherein the surface of the metamaterial comprises a plurality of posts with dimensions and spacing to cause the surface to generate the enhanced electric field at the desired frequency.

12. The system recited in claim 11, wherein deep space is used as a cold sink for the rectenna.

13. The system recited in claim 11, wherein the rectenna is placed in the near-field over each post at less than 0.5 wavelengths of the desired frequency.

14. The system recited in claim 11, wherein the post is has a height greater than one quarter of the wavelength of the desired frequency.

15. The system recited in claim 11, further comprising a thermally insulating and radiation transparent material surrounding each post.

16. The system recited in claim 11, further comprising an environmental overcoat to reflect away out-of-band energy.

17. The system recited in claim 11, wherein the desired frequency has a wavelength in the bands of one of 3 μ

m to 5 μ

m and 8 μ

m to 12 μ

m.