Reflective articles and methods for increasing photosynthesis

• US 9,320,201 B2
• Filed: 12/20/2013
• Issued: 04/26/2016
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: Elwha LLC (Intellectual Ventures LLC)
• Original Assignee: Elwha LLC (Intellectual Ventures LLC)
• Inventors: Duncan, William D., Hyde, Roderick A., Ishikawa, Muriel Y., Wood, Lowell L. Jr.
• Primary Examiner(s): Williams, Monica
• Assistant Examiner(s): WANG, MICHAEL H
• Application Number:
  US14/137,089
• Publication Number:
  US 20150173302A1
• Time in Patent Office: 858 Days
• Field of Search: 47/201, 47/291, 47/294, 47/581.LS
• US Class Current: 1/1
• CPC Class Codes: A01G 15/00 Devices or methods for influencing weather conditions
• CPC Class Codes: A01G 9/243 Collecting solar energy in general F24S
• CPC Class Codes: G02B 19/0019 having reflective surfaces only (e.g. louvre systems, systems with multiple planar reflectors)
• CPC Class Codes: G02B 19/0042 for use with direct solar radiation
• CPC Class Codes: G02B 27/143 using macroscopically faceted or segmented reflective surfaces
• CPC Class Codes: G02B 5/0236 the diffusion taking place within the volume of the element
• CPC Class Codes: G02B 5/0257 creating an anisotropic diffusion characteristic, i.e. distributing output differently in two perpendicular axes
• CPC Class Codes: G02B 5/0284 used in reflection
• CPC Class Codes: G02B 5/0294 adapted to provide an additional optical effect, e.g. anti-reflection or filter
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet
• CPC Class Codes: G02F 1/0126 Opto-optical modulation, i.e. control of one light beam by another light beam, not otherwise provided for in this subclass
• CPC Class Codes: G02F 1/0147 based on thermo-optic effects G02F1/132 takes precedence
• CPC Class Codes: Y02A 40/25 Greenhouse technology, e.g. cooling systems therefor
• CPC Class Codes: Y02P 60/12 using renewable energies, e.g. solar water pumping

Abstract

Provided is a reflective article including a first reflecting material and a second retro reflecting material; where sunlight that is photosynthetically active is at least partially reflected by the article and sunlight that is not photosynthetically active is at least partially retro reflected by the article. Also provided is a method for growing a plant, where the method includes placing the reflective article under, around, or in the proximity of the plant.

Claims

1. A reflective article configured for placement under, around, or in the proximity of a plant, comprising:

a first layer including reflecting material configured to diffusely reflect at least 80% of incident sunlight that is photosynthetically active; and

a second layer including retro-reflecting material configured to retro-reflect at least 80% of incident sunlight that is non-photosynthetically active;

wherein;

the first layer covers the second layer such that the incident light strikes the first layer before reaching the second layer;

the incident sunlight that is diffusely reflected excludes retro-reflecting the incident light;

sunlight that is photosynthetically active corresponds to wavelengths from about 400 nm to about 750 nm.

2. The reflective article of claim 1 comprising two or more layers.

3. The reflective article of claim 2, wherein at least one layer comprises the reflecting material and at least another layer comprises the retro-reflecting material.

4. The reflective article of claim 1, wherein the retro-reflecting material comprises corner-cube retro-reflectors.

5. The reflective article of claim 4, wherein the corner-cube retro-reflectors are about 0.005 cm to about 0.1 cm wide.

6. The reflective article of claim 1, wherein the retro-reflecting material comprises a metal.

7. The reflective article of claim 6, wherein the metal is stainless steel or aluminum.

8. The reflective article of claim 1, wherein at least one of the materials comprises a low emissivity film.

9. The reflective article of claim 1, wherein the article comprises a thermal insulator.

10. The reflective article of claim 1, wherein the reflective article comprises a film, foil, or sheet.

11. The reflective article of claim 1, wherein an efficiency with which sunlight is retro-reflected by the retro-reflecting material increases with increasing temperature of the article or the quantity of sunlight that contacts the article.

12. The reflective article of claim 1, wherein the sunlight that is diffusely reflected has an angle of reflection between 1 and 90 degrees relative to the angle of incidence of the sunlight.

13. The reflective article of claim 1 further comprising a spectrally transparent layer of material having a substantially smooth top surface and a diffusely reflective bottom surface, wherein the spectrally transparent layer of material comprises an array of concave indentations.

14. The reflective article of claim 13, wherein the substantially smooth top surface is at least partially specularly reflective of sunlight that is not photosynthetically active.

15. The reflective article of claim 13, wherein the spectrally transparent layer of material is at least partially transparent to sunlight that is photosynthetically active.

16. The reflective article of claim 13, wherein the diffusively reflective bottom surface is at least partially reflective of sunlight that is photosynthetically active.

17. The reflective article of claim 13, wherein the spectrally transparent layer of material has an irregular thickness.

18. The reflective article of claim 13, wherein the diffusely reflective bottom surface comprises a rough surface.

19. The reflective article of claim 13, wherein the diffusely reflective bottom surface comprises reflective particles.

20. The reflective article of claim 13, wherein the concave indentations are shaped such that the top surface forms corner-cube retro-reflectors.

21. The reflective article of claim 13, wherein the layer of material is disposed on a substrate, such that the substantially rough bottom surface comprises an interface between the layer of material and the substrate.

22. The reflective article of claim 1, wherein the reflecting material is consistently distributed throughout the reflective article.

23. The reflective article of claim 1, wherein the reflecting material is inconsistently distributed throughout the reflective article.

24. The reflective article of claim 1, wherein the reflective article is a ground cover.

25. The reflective article of claim 1, wherein the reflective article is configured to reduce a thermal emissivity of the ground covered by the article.

26. The reflective article of claim 1, wherein the article is substantially permeable to gas transfer between the atmosphere and the ground.

27. The reflective article of claim 1, wherein one or more of the reflective article(s) and the plant(s) are connected to a computer or a memory storage device.

28. A method for growing a plant comprising placing a reflective article under, around, or in the proximity of the plant, wherein the reflective article comprises

a first layer including reflecting material configured to diffusely reflect at least 80% of incident sunlight that is photosynthetically active;

and

a second layer including retro-reflecting material configured to retro-reflect at least 80% of incident sunlight that is non-photosynthetically active;

wherein;

the first layer covers the second layer such that the incident light strikes the first layer before reaching the second layer;

the incident sunlight that is diffusely reflected excludes retro-reflecting the incident light; and

sunlight that is photosynthetically active corresponds to wavelengths from about 400 nm to about 750 nm.

29. The method of claim 28, wherein an amount of water consumed by the plant is reduced by at least 10% after the article is placed.

30. The method claim 28, wherein the reflective article is placed over ground and a thermal emissivity of the ground is reduced by at least about 10%.