System and methods for plasma application

• US 8,994,270 B2
• Filed: 09/27/2010
• Issued: 03/31/2015
• Est. Priority Date: 05/30/2008
• Status: Active Grant

• Current Assignee: Colorado State University Research Foundation
• Original Assignee: Colorado State University Research Foundation
• Inventors: Koo, Il-Gyo, Moore, Cameron A., Collins, George J., Cho, Jin-Hoon
• Primary Examiner(s): Le, Tung X
• Assistant Examiner(s): COOPER, JONATHAN G
• Application Number:
  US12/924,404
• Publication Number:
  US 20110101862A1
• Time in Patent Office: 1,646 Days
• Field of Search: 315/111.21, 606/41, 606/34, 606/45, 606/49, 606/50, 606/9, 606/101
• US Class Current: 315/111.21
• CPC Class Codes: A61B 18/042 using additional gas becoming plasma
• CPC Class Codes: H01J 2237/332 Coating
• CPC Class Codes: H01J 2237/334 Etching
• CPC Class Codes: H01J 37/32018 Glow discharge
• CPC Class Codes: H01J 37/32366 Localised processing
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01J 37/32541 Shape
• CPC Class Codes: H01J 37/32559 Protection means, e.g. coatings
• CPC Class Codes: H01J 37/32568 Relative arrangement or disposition of electrodes; moving means
• CPC Class Codes: H01J 37/32577 Electrical connecting means
• CPC Class Codes: H05H 1/2431 using cylindrical electrodes, e.g. rotary drums
• CPC Class Codes: H05H 1/2441 characterised by the physical-chemical properties of the dielectric, e.g. porous dielectric
• CPC Class Codes: H05H 1/2443 the plasma fluid flowing through a dielectric tube
• CPC Class Codes: H05H 2245/32 Surgery, e.g. scalpels, blades or bistoury; Treatments inside the body

Abstract

The present disclosure provides for a plasma system. The plasma system includes a plasma device, an ionizable media source, and a power source. The plasma device includes an inner electrode and an outer electrode coaxially disposed around the inner electrode. The inner electrode includes a distal portion and an insulative layer that covers at least a portion of the inner electrode. The ionizable media source is coupled to the plasma device and is configured to supply ionizable media thereto. The power source is coupled to the inner and outer electrodes, and is configured to ignite the ionizable media at the plasma device to form a plasma effluent having an electron sheath layer about the exposed distal portion.

Claims

1. A plasma system, comprising:

a plasma device including an inner electrode and an outer electrode coaxially disposed around the inner electrode, wherein the inner electrode includes an end distal portion extending distally past a distal end of the outer electrode and an insulative layer that extends up to the distal end of the outer electrode and covers the inner electrode at least up to the end distal portion of the inner electrode such that the end distal portion of the inner electrode is un-insulated;

an ionizable media source coupled to the plasma device and configured to supply ionizable media thereto; and

a power source coupled to the inner and outer electrodes and configured to ignite the ionizable media at the plasma device to form a plasma effluent having an electron sheath layer about the end distal portion of the inner electrode.

2. A plasma system according to claim 1, wherein the insulative layer is configured to limit the plasma effluent to the end distal portion and to provide a source of secondarily-emitted electrons that form at least a part of the electron sheath layer.

3. A plasma system according to claim 2, wherein the insulative layer is formed from a material having a secondary electron emission yield from about 1 to about 10.

4. A plasma system according to claim 1, wherein the inner electrode is formed from a conductive metal and the insulative layer is a metallic oxide of the conductive metal.

5. A plasma system according to claim 1, wherein the plasma device further includes an electrode spacer disposed between the inner and outer electrodes.

6. A plasma system according to claim 5, wherein the electrode spacer includes a central opening defined therein and adapted for insertion of the inner electrode therethrough.

7. A plasma system according to claim 6, wherein the electrode spacer includes at least one flow opening defined therein and configured to receive the flow of the ionizable media, the at least one flow opening being disposed radially around the central opening.

22. The plasma system according to claim 1, wherein the end distal portion of the inner electrode is disposed in its entirety outside of the outer electrode.

8. A plasma device configured to receive ionizable media, comprising:

an outer electrode having a substantially cylindrical tubular shape; and

an inner electrode coaxially disposed within the outer electrode, the inner electrode including an end distal portion extending distally past a distal end of the outer electrode and an insulative layer that extends up to the distal end of the outer electrode and covers the inner electrode at least up to the end distal portion of the inner electrode such that the end distal portion of the inner electrode is un-insulated,

the insulative layer configured to limit plasma effluent to the end distal portion and to provide a source of secondarily-emitted electrons to form an electron sheath layer about the inner electrode end distal portion.

9. A plasma device according to claim 8, wherein the insulative layer is formed from a material having a secondary electron emission yield from about 1 to about 10.

10. A plasma device according to claim 8, wherein the inner electrode is formed from a conductive metal and the insulative layer is a metallic oxide of the conductive metal.

11. A plasma device according to claim 8, wherein the plasma device further includes an electrode spacer disposed between the inner and outer electrodes.

12. A plasma device according to claim 11, wherein the electrode spacer includes a central opening defined therein and adapted for insertion of the inner electrode therethrough.

13. A plasma device according to claim 12, wherein the electrode spacer includes at least one flow opening defined therein and configured to receive the flow of the ionizable media, the at least one flow opening being disposed radially around the central opening.

14. A plasma system, comprising:

an outer electrode having a substantially cylindrical tubular shape; and

an inner electrode coaxially disposed within the outer electrode, the inner electrode includes an end distal portion extending distally past a distal end of the outer electrode and an insulative layer that extends up to the distal end of the outer electrode and covers the inner electrode at least up to the end distal portion of the inner electrode such that the end distal portion of the inner electrode is un-insulated, the insulative layer configured to limit plasma effluent to the end distal portion and to provide a source of secondarily-emitted electrons;

an ionizable media source coupled to the plasma device and configured to supply ionizable media thereto; and

a power source coupled to the inner and outer electrodes and configured to ignite the ionizable media at the plasma device to form a plasma effluent having an electron sheath layer of a predetermined thickness formed from the secondarily-emitted electrons, the electron sheath layer being formed about the end distal portion of the inner electrode.

15. A plasma system according to claim 14, wherein the insulative layer is formed from a material having a secondary electron emission yield from about 1 to about 10.

16. A plasma system according to claim 14, wherein the inner electrode is formed from a conductive metal and the insulative layer is a metallic oxide of the conductive metal.

17. A plasma system according to claim 14, wherein the plasma device further includes an electrode spacer disposed between the inner and outer electrodes.

18. A plasma system according to claim 17, wherein the electrode spacer includes a central opening defined therein and adapted for insertion of the inner electrode therethrough.

19. A plasma system according to claim 18, wherein the electrode spacer includes at least one flow opening defined therein and configured for the flow of the ionizable media, the at least one flow opening being disposed radially around the central opening.

20. A plasma system according to claim 14, wherein the predetermined thickness of the electron sheath layer is adjusted by selecting a specific ionizable media having a predetermined media density and an average particle cross-section.

21. A plasma system according to claim 20, wherein the predetermined thickness of the electron sheath layer is inversely proportional to the media density of the ionizable media and the average particle cross-section.