Electret generator apparatus and method

• US 20040007877A1
• Filed: 06/04/2003
• Published: 01/15/2004
• Est. Priority Date: 06/07/2002
• Status: Abandoned Application

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology, Office of The Governor of Ohio (State of Ohio)
• Inventors: Tai, Yu-Chong, Boland, Justin
• Application Number:
  US10/455,755
• Publication Number:
  US 20040007877A1
• Time in Patent Office: Days
• US Class Current: 290/1R
• CPC Class Codes: H02N 1/08 with conductive charge carrier, i.e. capacitor machines

Abstract

An apparatus for power generation. The apparatus has a first substrate comprising a conductive surface region and a second substrate coupled to the first substrate. Preferably, the second substrate comprises an electret material region, which is characterized by a substantially uniform electric field associated with the electret material region. The conductive substrate and the electret substrate are aligned in a significantly parallel fashion with a common area of each region directly facing the other region (A). A distance (d) characterizing a spatial separation is formed between the conductive surface region and the electret material region. A relative voltage potential (V) between the conductive substrate and the electret substrate is associated with the distance (d). In between the conductive substrate and the electret substrate is a material, liquid, gas, or combination with an associated permittivity (ε₀). The relative voltage potential changes based upon a change in the spatial separation between (d), a change in the overlapping area (A), or a change in the permittivity (ε₀) between the conductive surface region and the electret material region.

Claims

1. A method for generating electricity, the method comprising:

moving an electret material surface relative to a conductive region, the conductive region being less than 20 square centimeters;

causing a change in relative voltage potential between the conductive region and the electret based upon at least a movement of the electret material surface relative to the conductive region.

2. The method of claim 1 wherein the conductive region is less than 10 square centimeters.

3. The method of claim 1 wherein the electret material comprises a peak to peak electric field uniformity directly above the surface of 5% and less or 1% and less.

4. The method of claim 1 wherein the electret material and the conductive material are maintained in environment free from moisture, moisture is being 50% RH and less.

5. The method of claim 1 wherein the electret material surface is maintained free from moisture.

6. The method of claim 1 further comprising outputting an alternating electric current from the varying voltage potential.

7. The method of claim 1 wherein the voltage potential difference is at least 1 volt between the conducting region and the electret region

8. The method of claim 1 further comprising applying a mechanical force to facilitate the movement of the electret material relative to the conductive region.

9. The method of claim 1 further comprising generating at least one microwatt of usable power.

10. The method of claim 1 wherein the movement is selected from translational, rotational, or vibrational.

11. Apparatus for generating electricity, the apparatus comprising:

an electret material surface;

a conductive surface region facing the electret material surface;

a dielectric material operably coupled between the electret surface and the conductive surface region to cause the relative potential between the conductive surface region and the electret to change based upon the varying spatial position of the dielectric material.

12. Apparatus of claim 11 wherein the dielectric material is a fluid.

13. Apparatus of claim 12 wherein the dielectric material fluid is water.

14. Apparatus of claim 11 wherein the dielectric material is a solid.

15. Apparatus of claim 11 wherein the conductive surface region further comprises a dielectric or electret material surface.

16. Apparatus of claim 11 wherein the electret material surface and the conductive surface region are separated by a predetermined distance.

17. Apparatus of claim 11 wherein the electret material surface and the conductive surface are configured in a substantially parallel manner.

18. Apparatus of claim 17 wherein the electret surface and the conductive surface include an electric field coupled between the electret surface and the conductive surface, the electric field having a direction normal to the electret surface and the conductive surface.

19. Apparatus of claim 11 wherein the electret material surface is one of a plurality of electret surface regions, each of the surface regions being separated by an inactive region.

20. Apparatus of claim 11 wherein the dielectric material is a conductive liquid.

21. Apparatus for power generation, the apparatus comprising:

a first substrate, the first substrate comprising a conductive surface region;

a second substrate coupled to the first substrate, the second substrate comprising an electret material region, the electret material region being characterized by a substantially uniform electric field associated with the electret material region;

a distance (d) characterizing a spatial separation between the conductive surface region and the electret material region;

a relative voltage potential between the conductive and the electret regions, the voltage potential being associated with the distance (d), whereupon the relative voltage potential changes based upon a change in the spatial separation between the conductive surface region and the electret material region.

22. The apparatus of claim 21 wherein the second substrate comprising:

a thickness of substrate material having a contact region;

a floating conducting region formed overlying the thickness of substrate material, the floating conducting region being free from physical contact with the contact region;

a protective layer formed overlying the floating conductive layer, the protective layer having a surface region, the surface region being free from physical contact with the floating conducting region;

whereupon the thickness of substrate material, the floating conducting region, and the protective layer form a sandwiched structure having a charge density of at least 1×

10<sup>−

4</sup> Coulombs/m² in magnitude and a peak to peak charge uniformity of 5% and less.

23. The apparatus of claim 22 wherein the floating conducting region is patterned using at least a micromachining process.

24. The apparatus of claim 22 wherein the thickness of substrate material is a Teflon®

material having a thickness of about 40 microns and less;

wherein the floating conducting region comprises an aluminum bearing material having a thickness of 5000 Angstroms and less.

25. The apparatus of claim 22 wherein the thickness of substrate material comprises Teflon®

material.

26. The apparatus of claim 22 wherein the floating conducting region comprises an aluminum bearing material or an aluminum alloy bearing material.

27. The apparatus of claim 22 wherein the protective layer is Teflon®

.

28. The apparatus of claim 22 wherein the floating conducting region is a single layer or multiple layers.

29. The apparatus of claim 22 wherein the protective layer is sputtered oxide, a polymer, or SOG.

30. The apparatus of claim 22 wherein the protective layer has a volume resistivity of greater than 1×

10¹³ Ohm cm

31. The apparatus of claim 22 wherein the floating conductive layer has a volume conductivity at least 1×

10<sup>−

10</sup> (Ohm cm)<sup>−

1</sup>.

32. The apparatus of claim 22 wherein the conductive layer has a resistivity value less than a resistivity value of the protective layer.

33. The apparatus of claim 22 wherein the charge density is provided by implantation of a plurality of electrons.

34. The apparatus of claim 22 wherein the plurality of electrons are provided by a e-beam.

35. The apparatus of claim 22 wherein the substrate is provided via spinning liquid Teflon®

material.

36. The apparatus of claim 22 wherein the substrate is provided via compression molding.

37. The apparatus of claim 22 wherein the substrate is selected from silicon, glass, and plastic.

38. The apparatus of claim 22 wherein the substrate contains an empty region or regions that contain gas or a low-conductivity liquid.

39. The apparatus of claim 22 wherein the substrate is provided on a mounting substrate to hold the substrate in place.

40. The apparatus of claim 38 wherein the mounting substrate comprises an overlying metal layer, the metal layer coupled to the substrate.

41. The apparatus of claim 22 wherein the substrate is made using damascene process.

42. The apparatus of claim 22 wherein floating conductive layer interacts with charge to facilitate the uniform distribution of charge.