Triboelectric nanogenerator for powering portable electronics

1. A triboelectric generator, comprising:

(a) a first contact charging member, including:

(i) a first contact layer, having a contact side and an opposite back side, including a material that has a triboelectric series rating indicating a propensity to exchange electrons due to a contacting event; and

(ii) a conductive electrode layer disposed along the back side of the contact layer;

(b) a second contact charging member, spaced apart from and disposed oppositely from the first contact charging member, including an electrically conductive material layer that has a triboelectric series rating indicating a propensity to exchange electrons when contacted by the first contact layer during the contacting event, the electrically conductive material layer configured to act as an electrode;

(c) a plurality of nano-scale structures extending from at least one of the first contact layer and the second contact charging member; and

(d) a mechanism configured to maintain a space between the first contact charging member and the second contact charging member except when a force is applied thereto.

2. The triboelectric generator of claim 1 , wherein the plurality of nano-scale structures includes structures selected from a list consisting of: pyramid-shaped nano-structures; box-shaped nano-structures; and nanoparticles.

3. The triboelectric generator of claim 2 , wherein the nanoparticles comprise gold nanoparticles.

4. The triboelectric generator of claim 1 , wherein the first contact layer comprises a material selected from a group consisting of: PDMS, PTFE, FEP, PVC, Polyimide and combinations thereof.

5. The triboelectric generator of claim 1 , wherein the first contact charging member has a concave shape, wherein the second contact charging member has a concave shape and wherein the mechanism configured to maintain space comprises the first contact charging member and the second contact charging member being disposed relative to each other so as to define the space therebetween.

6. The triboelectric generator of claim 5 , wherein the contact charging member comprises:

(a) a first substrate material layer; and

(b) a second substrate material layer disposed adjacent to the first substrate material layer, the second substrate material layer applied to the first substrate material layer at an elevated temperature and then cooled so that differential shrinkage during cooling causes the contact charging member to have a concave shape.

7. The triboelectric generator of claim 6 , wherein the first substrate material layer comprises a polymer sheet having a first thermal expansion coefficient and wherein the second substrate material layer comprises a ceramic film having a second thermal expansion coefficient that is less than the first thermal expansion coefficient.

8. The triboelectric generator of claim 6 , wherein the electrically conductive material layer comprises a material selected from a group consisting of: aluminum, a metal, a conductive polymer and combinations thereof.

9. The triboelectric generator of claim 1 , wherein the first contact charging member comprises a first rigid substrate to which the conductive electrode layer is affixed and wherein the second contact charging member comprises as second rigid substrate to which the electrically conductive material layer is affixed, and wherein the mechanism configured to maintain space comprises at least one spring disposed between the first rigid substrate and the second rigid substrate configured to maintain a space between the first contact layer and the electrically conductive material layer unless a force is applied thereto.

10. The triboelectric generator of claim 9 , wherein the conductive electrode layer comprises a material selected from a group consisting of: gold, a metal, ITO, a conducting polymer, and combinations thereof.

11. The triboelectric generator of claim 1 , wherein the electrically conductive material layer comprises a derivatized gold film, and wherein the nano-scale structures comprise a plurality of gold nanoparticles disposed on the derivatized gold film.

12. A triboelectric generating device, comprising:

(a) a first contact charging member, the first contact charging member including:

(i) a substrate layer having a first side and a second side, the substrate layer configured to maintain a concave shape unless a force is applied thereto;

(ii) a first contact layer, having a contact side, affixed to the first side of the substrate layer and including a material that has a triboelectric series rating indicating a propensity to gain electrons due to a contacting event; and

(iii) a conductive electrode layer affixed to the second side of the substrate layer;

(b) a second contact charging member, spaced apart from and disposed oppositely from the first contact charging member, including an electrically conductive metal layer that has a triboelectric series rating indicating a propensity to lose electrons when contacted by the first contact layer, the second contact charging member defining a concave shape that is reflective of the concave shape of the substrate layer; and

(c) a plurality of nano-scale structures extending from at least one of the first contact layer and the second contact charging member.

13. The triboelectric generating device of claim 12 , wherein the first contact layer comprises a material selected from a group consisting of: PDMS, PTFE, FEP, PVC, Polyimide and combinations thereof.

14. The triboelectric generating device of claim 12 , wherein the electrically conductive material layer comprises a material selected from a group consisting of: aluminum, a metal, a conductive polymer and combinations thereof.

15. The triboelectric generating device of claim 12 , wherein the substrate layer comprises:

(a) a first substrate material layer; and

(b) a second substrate material layer disposed adjacent to the first substrate material layer, the second substrate material layer applied to the first substrate material layer at an elevated temperature and then cooled so that differential shrinkage during cooling causes the contact charging member to have a concave shape.

16. The triboelectric generating device of claim 15 , wherein the first substrate material layer comprises poly(4,4′-oxydiphenylene-pyromellitimide) and wherein the second substrate material layer comprises SiO 2 .

17. A triboelectric generating system, comprising:

(a) a first contact charging member, including:

(i) a first rigid substrate;

(ii) a conductive electrode layer disposed on the substrate;

(iii) a first contact layer, disposed on the conductive electrode layer, including a material that has a triboelectric series rating indicating a propensity to gain electrons due to a contacting event; and

(b) a second contact charging member, spaced apart from and disposed oppositely from the first contact charging member, including:

(i) a second rigid substrate; and

(ii) an electrically conductive material layer that has a triboelectric series rating indicating a propensity to lose electrons when contacted by the first contact layer disposed on the second rigid substrate;

(c) at least one spring configured to maintain space between the first contact charging member and the second contact charging member except when a force is applied thereto; and

(d) a plurality of nano-scale structures extending from at least one of the first contact layer and the second contact charging member.

18. The triboelectric generating system of claim 17 , wherein the first contact layer comprises a material selected from a group consisting of: PDMS, PTFE, FEP, PVC, Polyimide and combinations thereof.

19. The triboelectric generating system of claim 17 , wherein the conductive electrode layer comprises a material selected from a group consisting of: gold, a metal, ITO, a conducting polymer, and combinations thereof.

20. The triboelectric generating system of claim 17 , wherein the electrically conductive material layer comprises a derivatized gold film and wherein the nano-scale structures include a plurality of gold nanoparticles disposed on the derivatized gold film.