PLASMA SOURCE AND APPLICATIONS THEREOF

• US 20070029500A1
• Filed: 05/16/2006
• Published: 02/08/2007
• Est. Priority Date: 08/05/2005
• Status: Active Grant

• Current Assignee: McGill University
• Original Assignee: Richard Leask, Sara Yonson, Sylvain Coulombe, Valerie Leveille
• Inventors: YONSON, SARA, COULOMBE, SYLVAIN, LEASK, RICHARD, LEVEILLE, VALERIE
• Granted Patent: US 7,608,839 B2
• Time in Patent Office: Days
• US Class Current: 250/423.F
• CPC Class Codes: A61C 19/063 Medicament applicators for teeth or gums, e.g. treatment with fluorides
• CPC Class Codes: H01T 23/00 Apparatus for generating ions to be introduced into non-enclosed gases, e.g. into the atmosphere
• CPC Class Codes: H05H 1/34 Details, e.g. electrodes, nozzles
• CPC Class Codes: H05H 1/475 Filamentary electrodes

Abstract

A low-power atmospheric pressure plasma source, comprising a plasma-forming region for injection of a plasma-forming gas; an excitation region for injection of a source reactive species downstream of the plasma-forming region; and a narrow converging plasma exit for producing a narrow plasma jet, the source being electrically decoupled from a substrate under treatment by the plasma jet. The present source may found applications for example for skin treatment, etching of skin cancer cells, detachment of cells, removal of skin pigmentation and deposition of temporary organic films.

Claims

1. A low-power atmospheric pressure plasma source, comprising:

a plasma-forming region;

an excitation region located downstream of said plasma-forming region; and

a narrow converging plasma exit;

wherein a plasma-forming gas is injected in said plasma-forming region at a flow rate of a few SLM and a source reactive species is injected in said excitation region, said source producing a narrow plasma jet through said narrow converging plasma exit.

2. The source of claim 1, said excitation region comprising a capillary electrode centered inside a plasma confinement tube, the plasma-forming gas flowing through an annular space defined between said capillary electrode and said plasma confinement tube, a converging nozzle of said plasma confinement tube forming said narrow converging plasma exit, a ground electrode being provided on an external surface of said plasma confinement tube.

3. The source of claim 2, wherein the source of reactive species is one of:

i) injected through said capillary electrode and ii) added to the plasma-forming gas.

4. The source of claim 3, the source generating reactive species from the source of reactive species injected through one of:

1) said capillary electrode, ii) air entrained in the plasma, and iii) the plasma forming gas.

5. The source of claim 1, the plasma-forming gas being one of He, Ar and N₂.

6. The source of claim 1, wherein the plasma is induced using a radio-frequency excitation.

7. The source of claim 6, the radio-frequency excitation being generated by an amplitude-modulated waveform generator.

8. The source of claim 1, operating at a power less than 5 W and voltage levels less than 600 Vpk-to-0.

9. The source of claim 1, the plasma-forming gas being He at a few SLM, the plasma jet produced having a diameter of less than 500 μ

m and a length of about 2.5 mm at power levels comprised in a range between 1 and 5 W, a breakdown voltage being about 220 V_pk-to-0.

10. The source of claim 1, a temperature of said plasma jet being compatible with bio-applications.

11. The source of claim 10, the temperature of said plasma jet being less that 50°

C. for a power level of about 1 W.

12. The source of claim 2, further comprising a first injection line for injecting the plasma-forming gas in a space created between said electrodes;

and a second injection line for injecting the source of reactive gas in one of said capillary electrode and said space created between said electrodes.

13. The source of claim 1, said source being one of:

i) handheld and ii) mounted on a robotic arm.

14. A plasma-assisted treatment system, comprising:

a source according to claim 2;

and

a radio frequency signal generator-amplifier-matching network system for powering the capillary electrode of said source; and

a gas delivery unit, which supplies gases to said source.

15. The source of claim 1, used for at least one of:

i) cell detachment, ii) cell functionalization and iii) cell permeabilization.

16. A method for cell modification using the source of claim 1.