Noble metal-polymer composites and flexible thin-film conductors prepared therefrom

• US 5,178,957 A
• Filed: 07/02/1991
• Issued: 01/12/1993
• Est. Priority Date: 05/02/1989
• Status: Expired due to Fees

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Williams, Paul M., Kolpe, Vasant V.
• Primary Examiner(s): HERBERT JR, THOMAS
• Application Number:
  US07/726,643
• Time in Patent Office: 560 Days
• Field of Search: 428/457, 428/141, 428/458, 128/784
• US Class Current: 428/458
• CPC Class Codes: A61B 2018/00107 Coatings on the energy applicator
• CPC Class Codes: A61N 1/04 Electrodes electrosurgical electrodes A61B18/14
• CPC Class Codes: C23C 14/20 on organic substrates
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 3/14 using spraying techniques to apply the conductive material , e.g. vapour evaporation
• CPC Class Codes: H05K 3/381 by special treatment of the substrate
• CPC Class Codes: H05K 3/388 by the use of a metallic or inorganic thin film adhesion layer
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]

Abstract

A composite article is prepared as a polymeric support having a coating of noble metal deposited on at least one surface thereof, the coating exhibiting suitable peel force for high performance applications such as the preparation of an electrode, such as a biocompatible, flexible, thin-film microelectrode where in the composite article can be prepared by pretreating at least one surface of the support by sputter etching, followed by sputter-depositing a noble metal on the pretreated surface in order to form the coating of noble metal.

Claims

1. A composite article comprising a polymeric support selected from the group consisting of a polyimide, polyethylene terephthalate, and polyester-ether block copolymer having a noble metal deposited directly onto at least one surface, wherein said deposited metal exhibits a peel force of at least about 0.05 kg per millimeter width after 24 hour boiling saline treatment.

2. A composite article according to claim 1 wherein said deposited metal is continuous and further exhibits

(1) sheet resistance of about 3 ohms per square or less before boiling saline treatment, and

(2) sheet resistance of about 9 ohms per square or less after 24 hour boiling saline treatment.

3. An article according to claim 1 wherein said polymeric support is polymidie.

4. An article according to claim 1 wherein said noble metal is selected from the group consisting of gold, iridium, palladium, platinum, rhodium, ruthenium, and their alloys.

5. An article according to claim 4 wherein said noble metal is platinum.

6. A multiconductor, microelectrode stimulation array fabricated from a composite article, said article comprising a polymeric support selected from the group consisting of a polymide, polyethylene terephthalate, and polyester-ether block copolymer, at least one surface of said support pretreated by sputter-etching and having a coating of a noble metal deposited thereon by sputter-deposition, wherein said coating exhibits a peel force of at least about 0.05 kg per millimeter width after 24 hour boiling saline treatment.

7. An array according to claim 6 wherein said polymeric support is polyimide.

8. An array according to claim 6 wherein said noble metal is selected from the group consisting of gold, iridium, palladium, platinum, rhodium, ruthenium, and their alloys.

9. An array according to claim 8 wherein said noble metal is platinum.

10. A composite article comprising a polymeric support selected from the group consisting of a polyimide, polyethylene terephthalate, and polyester-ether block copolymer having a coating of a noble metal deposited on at least one surface, wherein said article is prepared by a method comprising the steps of

(a) pretreating at least one surface of said polymeric support by sputter-etching, and

(b) sputter-depositing a noble metal on said pretreated surface in a manner that forms a coating comprising said noble metal deposited on said surface, said coating exhibiting a peel force suitable for its intended purpose.

11. A composite article according to claim 10 wherein said coating exhibits a peel force of at least about 0.05 kg per millimeter width after 24 hour boiling saline treatment.

12. A composite article according to claim 10 wherein said coating is continuous and further exhibits

(1) sheet resistance of about 3 ohms per square or less before boiling saline treatment, and

(2) sheet resistance of about 9 ohms per square or less after 24 hour boiling saline treatment.

13. A multicolor, microelectrode stimulation array prepared by a method comprising the steps of:

(1) preparing a composite article comprising a polymeric support selected from the group consisting of a polyimide, polyethylene terephthalate, and polyester-ether block copolymer, at least one surface of said support pretreated by sputter-etching and having a continuous coating of a noble metal deposited thereon by sputter-deposition, and

(2) fabricating said array from said composite article.