Plasma-assisted coating
Methods and apparatus are provided for igniting, modulating, and sustaining a plasma for various coating processes. In one embodiment, the surface of an object can be coated by forming a plasma in a cavity by subjecting a gas to an amount of electromagnetic radiation power in the presence of a plasma catalyst and adding at least one coating material to the plasma. The material is allowed to deposit on the surface of the object to form a coating. Various plasma catalysts are also provided. Coatings can include any material, for example, carbon nanotubes, BaTiO 3 , Cr 2 O 3 , hafnium oxide, 3Al 2 O 3 .2SiO 2 , Al 2 O 3 , SiAlON, MgAl 2 O 4 , TiN, and TiO 2 .
1 . A method of coating a first surface area of an object, comprising:
forming a plasma in a first cavity at atmospheric pressure by subjecting a gas to microwave radiation in the presence of a plasma catalyst;
adding at least one coating material to the plasma; and
allowing the at least one material to deposit on the surface area of the object to form a coating.
2 . The method of claim 1 , wherein the catalyst comprises at least one of metal, inorganic material, carbon, carbon-based alloy, carbon-based composite, electrically conductive polymer, conductive silicone elastomer, polymer nanocomposite, and an organic-inorganic composite.
3 . The method of claim 1 , wherein the catalyst is in the form of at least one of a nano-particle, a nano-tube, a powder, a dust, a flake, a fiber, a sheet, a needle, a thread, a strand, a filament, a yarn, a twine, a shaving, a sliver, a chip, a woven fabric, a tape, and a whisker.
4 . The method of claim 1 , further comprising controlling a temperature associated with the plasma according to a predetermined temperature profile by varying at least one of a gas flow through the cavity and an electromagnetic radiation power level.
5 . The method of claim 1 , wherein the cavity is formed in a vessel and substantially confines the plasma.
6 . The method of claim 1 , wherein forming a plasma in the first cavity includes forming the plasma with argon gas.
7 . The method of claim 1 , further comprising adding acetylene to the plasma and allowing carbon nanotubes to be deposited on the coating.
8 . The method of claim 7 , wherein the first cavity is an annular cavity.
9 . The method of claim 1 , wherein the at least one coating material includes Barium, Titanium, and Oxygen and the coating is BaTiO 3 .
10 . The method of claim 1 , wherein the at least one coating material includes chromium and oxygen and the coating is Cr 2 O 3 .
11 . The method of claim 10 , wherein the object is metallic.
12 . The method of claim 1 , wherein the at least one coating material includes Hafnium and oxygen and the coating is Hafnium oxide.
13 . The method of claim 12 , wherein the object is silicon.
14 . The method of claim 1 , wherein the at least one coating material includes aluminum, silicon, and oxygen and the coating is 3Al 2 O 3 .2SiO 2 .
15 . The method of claim 1 , wherein the at least one coating material includes aluminum and oxygen and the coating is Al 2 O 3 .
16 . The method of claim 15 , wherein the object is a polymer.
17 . The method of claim 1 , wherein the at least one coating material includes silicon, aluminum, nitrogen, and oxygen and the coating is SiAlON.
18 . The method of claim 1 , wherein the at least one coating material includes magnesium, aluminum, and oxygen and the coating is MgAlO 4
19 . The method of claim 18 , wherein the object is a metal.
20 . The method of claim 1 , wherein the at least one coating material includes titanium and nitrogen and the coating is TiN.
21 . The method of claim 20 , wherein the object is a ceramic.
22 . The method of claim 21 , wherein the ceramic is Al 2 O 3 .
23 . The method of claim 1 , wherein the at least one coating material includes titanium and oxygen and the coating is TiO 2 .
24 . The method of claim 23 , wherein the object is a glass.
25 . The method of claim 23 , wherein the object is a metal.
26 . A material deposition system comprising:
a first vessel in which a first cavity is formed;
an electromagnetic radiation source configured to direct electromagnetic radiation into the first cavity during deposition;
a gas source coupled to the first cavity such that a gas can flow into the cavity during deposition; and
a plasma catalyst,
wherein a plasma is ignited in the first cavity when the electromagnetic radiation is incident on a first gas from the gas source and deposition of a coating on an object occurs in the presence of the second gas.
27 . The system of claim 26 , wherein the first gas is argon.
28 . The method of claim 26 , wherein the gas includes acetylene and the coating includes carbon nanotubes.
29 . The method of claim 28 , wherein the first cavity is an annular cavity.
30 . The method of claim 26 , wherein the gas includes Barium, Titanium, and Oxygen and the coating is BaTiO 3 .
31 . The method of claim 26 , wherein the gas includes chromium and oxygen and the coating is Cr 2 O 3 .
32 . The method of claim 31 , wherein the object is metallic.
33 . The method of claim 26 , wherein the gas includes Hafnium and oxygen and the coating is Hafnium oxide.
34 . The method of claim 33 , wherein the object is silicon.
35 . The method of claim 26 , wherein the gas includes aluminum, silicon, and oxygen and the coating is 3Al 2 O 3 .2SiO 2 .
36 . The method of claim 26 , wherein the gas includes aluminum and oxygen and the coating is Al 2 O 3 .
37 . The method of claim 36 , wherein the object is a polymer.
38 . The method of claim 26 , wherein the gas includes silicon, aluminum, nitrogen, and oxygen and the coating is SiAlON.
39 . The method of claim 26 , wherein the gas includes magnesium, aluminum, and oxygen and the coating is MgAlO 4
40 . The method of claim 39 , wherein the object is a metal.
41 . The method of claim 26 , wherein the gas includes titanium and nitrogen and the coating is TiN.
42 . The method of claim 41 , wherein the object is a ceramic.
43 . The method of claim 42 , wherein the ceramic is Al 2 O 3 .
44 . The method of claim 26 , wherein the gas includes titanium and oxygen and the coating is TiO 2 .
45 . The method of claim 44 , wherein the object is a glass.
46 . The method of claim 44 , wherein the object is a metal.