Method and apparatus for providing a conductive, amorphous non-stick coating

• US 6,270,831 B2
• Filed: 04/30/1998
• Issued: 08/07/2001
• Est. Priority Date: 04/30/1998
• Status: Expired due to Fees

• Current Assignee: World Heart Corporation (Medtronic Plc), Utah State University
• Original Assignee: Medquest Products, Inc. (Maverick Venture Management LLC), University of Utah Research Foundation (State of Utah)
• Inventors: Kumar, B. Ajit, Khanwilkar, Pratap, Olsen, Don B.
• Primary Examiner(s): PIANALTO, BERNARD D
• Application Number:
  US09/071,371
• Publication Number:
  US 20010002000A1
• Time in Patent Office: 1,195 Days
• Field of Search: 204/192.1, 427/126.1, 427/127, 427/128, 427/2.1, 427/2.24, 427/2.3, 427/162, 427/165, 427/255.4, 427/399, 438/1
• US Class Current: 427/2.24
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 2017/0088 ceramic
• CPC Class Codes: A61B 2018/00077 high, i.e. electrically conducting
• CPC Class Codes: A61B 2018/00107 Coatings on the energy applicator
• CPC Class Codes: A61B 2018/00119 with metal oxide nitride
• CPC Class Codes: A61B 2018/00148 with metal
• CPC Class Codes: A61M 60/268 the displacement member being flexible, e.g. membranes, diaphragms or bladders
• CPC Class Codes: A61M 60/871 Energy supply devices; Converters therefor
• CPC Class Codes: C23C 14/0641 Nitrides C23C14/0617 takes precedence

Abstract

A conductive, non-stick coating is provided using a ceramic material which is conductive, flexible and provides a surface which exhibits the property of lubricity. A room or near room temperature manufacturing process produces a coating of titanium nitride on a substrate, where the coating is amorphous if the substrate is a solid material including plastics, composites, metals, magnets, and ceramics, enabling the substrate to bend without damaging the coating. The coating can also be applied as a conformal coating on a variety of substrate shapes, depending upon the application. The coating is bio-compatible and can be applied to a variety of medical devices.

Claims

1. A method for providing a wear-resistant ceramic coating on a substrate which is used in an abrasive environment, such that the substrate is not deformed during a process of applying the wear-resistant ceramic coating to the substrate, said method comprising the steps of:

selecting at least one ceramic from a group of ceramics consisting of transition metal nitrides;

using a generally room temperature application process to apply said at least one selected ceramic as an angstrom-thick, continuous, conductive and amorphous ceramic coating directly on the substrate in the absence of a sub-coating;

said amorphous ceramic coating bonding to the substrate by way of an interfacial nanometer-thick bonding layer that consists of both the substrate and said at least one selected ceramic;

the substrate not being damaged by said generally room temperature application process;

said amorphous ceramic coating being characterized as not having a crystalline structure;

said amorphous coating having no grain boundaries; and

said amorphous coating having uniform properties and deformation behavior at the nanometer level, thereby enabling the substrate and said amorphous ceramic coating to be deformed without fracturing.

2. The method defined in claim 1 wherein the method further comprises the step of applying at least one material which is not a transition metal nitride to said amorphous ceramic coating.

3. The method defined in claim 1 wherein said amorphous ceramic coating is electrically conductive to thereby facilitate propagation of electrical energy within said amorphous ceramic coating.

4. The method defined in claim 1 wherein said amorphous ceramic coating is not worn away by application of RF energy thereto, by abrasion or by sterilization.

5. The method defined in claim 1 wherein the method further comprises the step of physically deforming the substrate from a resting state, and wherein said amorphous ceramic coating deforms as the substrate is deformed, without damage to said amorphous ceramic coating.

6. The method defined in claim 1 wherein said amorphous ceramic coating is a corrosion resistant amorphous ceramic coating.

7. The method defined in claim 1 wherein said amorphous ceramic coating is a fatigue resistant amorphous ceramic coating.

8. The method defined in claim 1 wherein said amorphous ceramic coating is sterilizable and biocompatible.

9. The method defined in claim 1 wherein said amorphous ceramic coating is radio frequency opaque.

10. The method defined in claim 1 wherein said amorphous ceramic coating is a generally smooth and non-stick amorphous ceramic coating.

11. The method defined in claim 1 wherein said at least one selected ceramic is titanium nitride.

12. The method defined in claim 1 wherein the substrate is selected from a group consisting of plastic, glass, ceramic, metal, composites, magnetic material and semiconductor.

13. The method defined in claim 1 wherein said amorphous ceramic coating forms a shield against electro magnetic interference.

14. The method defined in claim 1 wherein said amorphous ceramic coating is a chemically inert and chemically stable amorphous ceramic coating.

15. The method defined in claim 1 wherein said amorphous ceramic coating forms a diffusion barrier that inhibits fluids and gases passing through said amorphous ceramic coating.

16. The method defined in claim 15 wherein the substrate member and said amorphous ceramic coating are flexible to thereby enable flexing of the substrate without damaging said diffusion barrier.

17. The method defined in claim 16 wherein said diffusion barrier operates to inhibit exchange of gases or fluids through said diffusion barrier.

18. The method defined in claim 17 wherein the substrate is a flexible membrane that is permeable by fluids and gases.

19. The method defined in claim 1 including the steps of:

providing a single assembly having a plurality of different substrate members; and

applying said amorphous ceramic coating to said plurality of different substrate members such that said amorphous ceramic coating is applied to all surfaces of said single assembly.

20. The method defined in claim 1 wherein the substrate is selected from a group of magnetic members consisting of magnetic tape, ceramic magnets, rare-earth magnets, metallic magnets, and wherein said selected magnetic member is protected from moisture by said amorphous ceramic coating.

21. The method defined in claim 1 wherein the substrate is rotatable magnetic media, and wherein said amorphous ceramic coating reduces a surface friction of said rotatable magnetic media.

22. The method defined in claim 1 wherein said amorphous ceramic coating provides protection from EMI and RFI.

23. A method for providing a ceramic coating on a semiconductor material, said method comprising the steps of:

selecting a ceramic from a group of ceramics consisting of transition metal nitrides;

using a generally room temperature application process to apply said selected ceramic as a thin amorphous ceramic coating directly onto the semiconductor material in the absence of a sub-coating;

said amorphous ceramic coating bonding to the semiconductor material by way of an interfacial nanometer thick bonding layer that consists of both the semiconductor material and said selected ceramic; and

said amorphous ceramic coating forming a continuous, conductive, and amorphous coating which is not characterized as having a crystalline structure, to thereby enable said amorphous ceramic coating to be deformed without fracturing.

24. A method for providing a wear-resistant ceramic coating on a magnetic member whose magnetic properties can be damaged by thermal energy, such that the magnetic member retains its magnetic properties during a process of applying the wear-resistant ceramic coating to the magnetic member, said method comprising the steps of:

selecting a ceramic from a group of ceramics consisting of transition metal nitrides;

using a generally room temperature application process to apply said selected ceramic directly to the magnetic member in the absence of a sub-coating and as a thin and continuous amorphous coating;

said amorphous coating bonding to the magnetic member by way of an interfacial nanometer-thick bonding layer that consists of both the magnetic member and said selected ceramic;

the properties of the magnetic material not being damaged by thermal energy of said generally room temperature application process; and

said amorphous coating being a coating that does not have a crystalline structure, to thereby enable said amorphous coating to deform without fracturing.

25. A method for providing a wear-resistant ceramic coating on a heat-sensitive member which is used in an abrasive environment, such that the heat-sensitive member is not damaged or degraded during a process of applying the wear-resistant ceramic coating onto the heat-sensitive member, said method comprising the steps of:

selecting a ceramic from a group of ceramics consisting of transition metal nitrides;

using a generally room temperature application process to apply said selected ceramic as an angstroms-thick, wear-resistant, ceramic coating directly on the heat-sensitive member in the absence of a sub-coating;

said wear-resistant ceramic coating bonding to the heat-sensitive member by way of an interfacial thick-thick bonding layer that consists of both the heat-sensitive member and said selected ceramic;

the heat-sensitive material not being deformed by heat generated by said generally room temperature application process;

said wear-resistant ceramic coating forming a continuous, conductive, and amorphous coating on the heat-sensitive member; and

said wear-resistant ceramic coating not having a crystalline structure, to thereby enable said wear-resistant ceramic coating to be deformed without fracturing said wear-resistant ceramic coating.

26. A method for providing a wear-resistant ceramic coating on a material that is usable in an environment that is detrimental to the material, such that the material is covered with a continuous, smooth and fatigue-resistant ceramic coating, said method comprising the steps of:

selecting a ceramic from a group of ceramics consisting of transition metal nitrides;

using a generally room temperature application process to apply said selected ceramic as an angstroms-thick, wear-resistant, ceramic coating directly on the material in the absence of a sub-coating;

said wear-resistant ceramic coating bonding to the material by way of an interfacial nanometer-thick bonding layer that consists of both the material and said selected ceramic;

said wear-resistant ceramic coating enhancing wear-resistance, lubricity and strength of the material; and

said wear-resistant ceramic coating being a continuous, conductive, and amorphous ceramic coating that cannot be characterized as having a crystalline structure, to thereby enable the wear-resistant coating to be deformed without fracturing.

27. The method defined in claim 26 wherein the material is selected from a group of products consisting of kitchen utensils, gears, spark plugs, molds, plumbing fixtures, eyeglass frames, cutting instruments, moisture barriers, sporting goods, writing instruments, drilling instruments, fasteners, bearings, bushings, electrical devices, semiconductors, jewelry, engine components, toys, packaging, optical instruments, fuel cells, and recording media.

28. A method for providing a wear-resistant ceramic coating on a ceramic member which can be damaged by thermal energy, such that the ceramic member is not damaged during a process of applying the wear-resistant ceramic coating to the ceramic member, said method comprising the steps of:

providing a quantity of titanium nitride ceramic;

using a generally room temperature application process to apply said titanium nitride ceramic as an angstrom-thick, wear-resistant, ceramic coating directly to the ceramic member in the absence of a sub-coating, and such that the ceramic member is not damaged by said generally room temperature application process;

said wear-resistant ceramic coating bonding to the ceramic member by way of an interfacial nanometer-thick bonding layer that consists of both the ceramic member and said titanium nitride ceramic;

said wear-resistant ceramic coating forming a continuous, conductive, and amorphous ceramic coating on the ceramic member that does not have a crystalline structure, to thereby enable said wear resistant coating to be deformable without fracturing.

29. A method providing a bio-compatible coating on a temperature-sensitive member used in a medical device such that the temperature sensitive member is not damaged during a process that applies the bio-compatible coating to the temperature sensitive member, said method comprising the steps of:

selecting a ceramic from a group of ceramics consisting of transition metal nitrides;

using a generally room temperature application process to apply said selected ceramic as a thin bio-compatible ceramic coating directly on the temperature-sensitive member in the absence of a sub-coating, such that the temperature-sensitive member is not damaged by thermal energy of said generally room temperature application process;

said bio-compatible ceramic coating bonding to the temperature-sensitive member by way of a nanometer-thick interfacial layer that consists of both said selected ceramic and the temperature-sensitive member;

said bio-compatible ceramic coating forming a continuous, conductive, and amorphous coating not having a crystalline structure, to thereby enable the bio-compatible ceramic coating to be deformable without fracturing; and

placing the temperature-sensitive member and its bio-compatible ceramic coating in the medical device, to thereby enable the medical device to be utilized in a medical environment.

30. The method defined in claim 29 wherein the temperature sensitive member is selected from a group consisting of plastic, glass, and magnetic materials.

31. The method defined in claim 30 wherein said selected ceramic provides corrosion resistance.

32. The method defined in claim 30 wherein said selected ceramic provides lubricity.

33. The method defined in claim 29 wherein the temperature-sensitive member is a plastic introducer catheter which is easily inserted due to said lubricity.

34. The method defined in claim 29 wherein the temperature-sensitive member is at least one permanent magnet used in an implantable medical device that requires at least one electromagnetic device for operation of the implantable medical device.

35. A method for utilizing a nonbio-compatible member in an implantable medical device, wherein the implantable medical device is made safe for implantation, said method comprising the steps of:

selecting a bio-compatible ceramic from a group of ceramics consisting of transition metal nitrides;

using a generally room temperature application process to apply said selected bio-compatible ceramic as an amorphous coating directly onto the nonbio-compatible member in the absence of a sub-coating;

said amorphous coating having a thickness in the range of from about 5,000 to about 10,000 angstroms;

said amorphous coating bonding to the nonbio-compatible member by way of an nanometer-thick interfacial layer that consists of both said selected bio-compatible ceramic and the nonbio-compatible member;

said amorphous coating forming a continuous, conductive, and amorphous coating that completely covers the nonbio-compatible member;

said amorphous coating having substantially no crystalline structure, to thereby enable said amorphous coating to be deformable without fracturing; and

placing the coated nonbio-compatible member in the implantable medical device.

36. The method defined in claim 35 wherein the nonbio-compatible member is selected from a group of temperature-sensitive members consisting of plastic, glass, and magnetic members.

37. The method defined in claim 35 wherein the implantable device is selected from a group consisting of stents, ventricular assist devices, pumps, impellers, balloons, diaphragms, volume displacement chambers, plastic tubes providing fluid paths, bearings, bearing components, catheters, occluders, soft tissue implants, valves, shunts, pacemakers, defibrillators, cardioverters, electrodes, neural stimulators, filters, grafts, patches, contraceptive devices, sensors, transducers, needles, medical tubes, clips, surgical staples, prostheses and electrosurgical blades.

38. A method for creating a diffusion barrier within a medical device, the diffusion barrier being disposed on a permeable membrane through which fluids and gases will normally diffuse, said method comprising the steps of:

selecting a ceramic from a group consisting of titanium nitride, aluminum oxide, titanium carbide, silicon carbide, silicon nitride, born nitride and zirconia;

using a generally room temperature process to apply said selected ceramic directly onto the permeable membrane as a diffusion barrier in the absence of a sub-coating;

said diffusion barrier being from about 5,000 to about 10,000 angstroms thick;

said diffusion barrier bonding to the permeable membrane by way of a nanometer-thick interfacial layer that consists of both said selected ceramic and the permeable membrane;

said diffusion barrier forming a continuous amorphous coating on the permeable membrane;

said diffusion barrier having no appreciable crystalline structure; and

said diffusion barrier reducing penetration of fluids and gases through the permeable membrane.

39. The method defined in claim 38 wherein the permeable membrane operates to reduce an exchange of working fluids that are within the medical device and body fluids that are within a body in which the medical device is implanted.