System and Method for Directed Self-Assembly Technique for the Creation of Carbon Nanotube Sensors and Bio-Fuel Cells on Single Plane

• US 20100279179A1
• Filed: 03/12/2010
• Published: 11/04/2010
• Est. Priority Date: 06/20/2007
• Status: Active Grant

• Current Assignee: New Jersey Institute of Technology
• Original Assignee: New Jersey Institute of Technology
• Inventors: Kanwal, Alokik, Farrow, Reginald C., Iqbal, Zafar
• Granted Patent: US 8,546,027 B2
• Time in Patent Office: Days
• US Class Current: 429/401
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01M 8/16 Biochemical fuel cells, i.e. cells in which microorganisms function as catalysts
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

Improved nanotube devices and systems/methods for fabrication thereof are provided. The present disclosure provides systems/methods for depositing controlled numbers of nanotubes with specific properties at predefined locations for the fabrication of nanotube devices. The nanotube devices may be utilized in a range of applications. A bio-fuel cell system that does not require a proton exchange membrane separator and does not need a mediator to transfer charge is provided. This exemplary bio-fuel cell uses enzyme functionalized SWNTs for the anode/cathode. The absence of a membrane in the bio-fuel cell configuration opens up the possibility of other configurations that would otherwise be unfeasible. This includes a bio-fuel cell where the anode/cathode are on the same substrate. Since the electrodes can share the same substrate, the configuration may be integrated with a circuit device on the same substrate. An IC and its power source may be fabricated on the same silicon wafer.

Claims

1. A bio-fuel cell comprising:

a substrate having positioned thereon a first conductive member and a second conductive member with an insulating layer positioned over the substrate and the first and second conductive members, the insulating layer;

(i) having a first aperture formed therein exposing a first region of the first conductive member, with an electrophoretically deposited first nanotube having a first end in contact with the exposed first region of the first conductive member, and (ii) having a second aperture formed therein exposing a second region of the second conductive member, with an electrophoretically deposited second nanotube having a first end in contact with the exposed second region of the second conductive member;

the first nanotube electrically coupled to the second nanotube, the first nanotube configured to be a cathode and the second nanotube configured to be an anode; and

an electrolyte in electrical communication with the cathode and the anode.

2. The bio-fuel cell of claim 1, wherein the insulating layer is configured to generate an electric field around the first and second apertures;

wherein the first and second apertures are each sized to allow a plurality of nanotubes to contact the exposed first and second regions of the first and second conductive members; and

wherein after the first and second nanotubes are electrophoretically deposited, the deposited first and second nanotubes are each adapted to reconfigure the electric field to thereby prevent other nanotubes from the plurality of nanotubes from being deposited on the exposed first and second regions of the first and second conductive layers.

3. The bio-fuel cell of claim 1, wherein the first and second apertures each have a diameter of at least about 40 nm.

4. The bio-fuel cell of claim 1, wherein a top surface of the substrate defines a horizontal plane;

and

wherein the first and second conductive members are both positioned on the horizontal plane of the substrate.

5. The bio-fuel cell of claim 4, wherein the deposited first and second nanotubes are oriented substantially perpendicular with respect to the horizontal plane.

6. The bio-fuel cell of claim 1, wherein the bio-fuel cell does not require a proton exchange membrane or mediator molecules to transfer charges to the anode and cathode.

7. The bio-fuel cell of claim 1, wherein the cathode and anode are configured to provide electrical power to an electrical device.

8. The bio-fuel cell of claim 7, wherein the electrical device is positioned at least in part on the substrate.

9. The bio-fuel cell of claim 8, wherein the cathode and anode are integrated with the electrical device.

10. The bio-fuel cell of claim 7, wherein the electrical device is an integrated circuit;

and

wherein the substrate is silicon.

11. The bio-fuel cell of claim 10, wherein the integrated circuit is a complementary metal oxide semiconductor integrated circuit.

12. The bio-fuel cell of claim 11, wherein the cathode is connected to a negative supply for a nMOS circuit and the anode is connected to a positive supply for a pMOS circuit.

13. The bio-fuel cell of claim 1, wherein the first and second nanotubes are partially carboxylated nanotubes.

14. The bio-fuel cell of claim 1, wherein the cathode is functionalized with a first enzyme after deposition;

and

wherein the anode is functionalized with a second enzyme after deposition.

15. The bio-fuel cell of claim 14, wherein the first enzyme is laccase and the second enzyme is glucose oxide.

16. The bio-fuel cell of claim 1 further comprising:

an electrophoretically deposited third nanotube having a first end in contact with the exposed first region of the first conductive member;

an electrophoretically deposited fourth nanotube having a first end in contact with the exposed second region of the second conductive member;

the first and third nanotubes configured to be the cathode and the second and fourth nanotubes configured to be the anode.

17. The bio-fuel cell of claim 1 further comprising:

a first network of a first plurality of nanotubes associated with the first nanotube and a second network of a second plurality of nanotubes associated with the second nanotube;

the first nanotube and the first network configured to be the cathode and the second nanotube and the second network configured to be the anode.

18. A method of fabricating a bio-fuel cell comprising:

providing a substrate having positioned thereon a first conductive member and a second conductive member with an insulating layer positioned over the substrate and the first and second conductive members;

forming a first aperture in the insulating layer to expose a first region of the first conductive member;

forming a second aperture in the insulating layer to expose a second region of the second conductive member;

generating an electric field proximate to the first and second apertures, the electric field configured to direct a plurality of nanotubes towards the first and second exposed regions of the first and second conductive members;

depositing a first nanotube on the first exposed region of the first conductive member and a second nanotube on the second exposed region of the second conductive member by electrophoresis, the deposited first nanotube having one end contacting the first exposed region of the first conductive member and the deposited second nanotube having one end contacting the second exposed region of the second conductive member;

configuring the first nanotube to be a cathode and the second nanotube to be an anode;

electrically coupling the cathode to the anode; and

providing an electrolyte in electrical communication with the cathode and anode.

19. The method of claim 18, wherein the first and second apertures are each sized to allow a plurality of nanotubes to contact the exposed first and second regions of the first and second conductive members;

and

wherein after the first and second nanotubes are deposited, the deposited first and second nanotubes are each adapted to reconfigure the electric field to thereby prevent other nanotubes from the plurality of nanotubes from being deposited on the exposed first and second regions of the first and second conductive layers.

20. The method of claim 18, wherein the first and second apertures each have a diameter of at least about 40 nm.

21. The method of claim 18, wherein a top surface of the substrate defines a horizontal plane;

and

wherein the first and second conductive members are both positioned on the horizontal plane of the substrate.

22. The method of claim 21, wherein the deposited first and second nanotubes are oriented substantially perpendicular with respect to the horizontal plane.

23. The method of claim 18, wherein the fabricated bio-fuel cell does not require a proton exchange membrane or mediator molecules to transfer charges to the anode and cathode.

24. The method of claim 18 further comprising configuring the cathode and anode to provide electrical power to an electrical device.

25. The method of claim 24 further comprising positioning the electrical device at least in part on the substrate.

26. The method of claim 25 further comprising integrating the cathode and anode with the electrical device.

27. The method of claim 26, wherein the electrical device is an integrated circuit;

and

wherein the substrate is silicon.

28. The method of claim 27, wherein the integrated circuit is a complementary metal oxide semiconductor integrated circuit.

29. The method of claim 18 further comprising connecting the cathode to a negative supply for a nMOS circuit and connecting the anode to a positive supply for a pMOS circuit.

30. The method of claim 18, wherein the first and second nanotubes are partially carboxylated nanotubes.

31. The method of claim 18, wherein the configuring the first nanotube to be the cathode step includes functionalizing the first nanotube with a first enzyme after deposition of the first nanotube;

and

wherein the configuring the second nanotube to be the anode step includes functionalizing the second nanotube with a second enzyme after deposition of the second nanotube.

32. The method of claim 18, wherein the first enzyme is laccase and the second enzyme is glucose oxide.

33. The method of claim 18 further comprising:

associating a first network of a first plurality of nanotubes with the first deposited nanotube and associating a second network of a second plurality of nanotubes with the second nanotube;

configuring the first nanotube and the first network to be the cathode and configuring the second nanotube and the second network to be the anode.

34. A method of fabricating a bio-fuel cell comprising:

providing a substrate having positioned thereon a first conductive member and a second conductive member with an insulating layer positioned over the substrate and the first and second conductive members;

forming a first elongated aperture in the insulating layer to expose a first region of the first conductive member, the first elongated aperture having a first width and a first length larger than the first width;

forming a second elongated aperture in the insulating layer to expose a second region of the second conductive member, the second elongated aperture having a second width and a second length larger than the second width;

generating an electric field proximate to the first and second apertures, the electric field configured to direct a first plurality of nanotubes towards the first and second exposed regions of the first and second conductive members;

depositing;

(i) a second plurality of nanotubes in a first line pattern on the first exposed region of the first conductive member, and (ii) a third plurality of nanotubes in a second line pattern on the second exposed region of the second conductive member, by electrophoresis;

configuring at least a first nanotube from the second plurality to be a cathode and configuring at least a second nanotube from the third plurality to be an anode;

electrically coupling the cathode to the anode;

providing an electrolyte in electrical communication with the cathode and anode;

wherein the width of the first aperture is sufficiently small to restrict deposition of the second plurality of nanotubes to the first line pattern and the number of nanotubes in the second plurality is determined at least in part by the length of the aperture;

wherein the width of the second aperture is sufficiently small to restrict deposition of the third plurality of nanotubes to the second line pattern and the number of nanotubes in the second plurality is determined at least in part by the length of the aperture;

wherein the number of nanotubes in the first plurality of nanotubes is greater than the number of nanotubes in the second plurality of nanotubes, and wherein the number of nanotubes in the first plurality of nanotubes is greater than the number of nanotubes in the third plurality of nanotubes.

35. The method of claim 34, wherein after the second and third plurality of nanotubes are deposited, the deposited second and third plurality of nanotubes each re-configure the electric field to thereby prevent other nanotubes from the first plurality of nanotubes from being deposited on the first and second exposed regions of the first and second conductive members.