Flexible electrically conductive nanotube sensor for elastomeric devices

• US 8,746,075 B2
• Filed: 08/30/2012
• Issued: 06/10/2014
• Est. Priority Date: 02/16/2012
• Status: Active Grant

• Current Assignee: 7-Sigma Inc.
• Original Assignee: 7-Sigma Inc.
• Inventors: Eichhorn, Wade R., Duda, Richard, Wyrobek, Kristian G., Sezen, Ahmet Serdar
• Primary Examiner(s): Noori, Max
• Application Number:
  US13/599,935
• Publication Number:
  US 20130213140A1
• Time in Patent Office: 649 Days
• Field of Search: 737/60, 73773-777
• US Class Current: 73/777
• CPC Class Codes: A61B 2562/0261 Strain gauges
• CPC Class Codes: A61B 2562/0285 Nanoscale sensors
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 5/6853 with a balloon
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: G01L 1/2206 Special supports with preselected places to mount the resistance strain gauges; Mounting of supports
• CPC Class Codes: G01L 9/0035 using variations in ohmic resistance

Abstract

A flexible substrate has a major surface and a sensor attached to and aligned with the major surface of the substrate. The sensor may have an elastic body containing conductive nanotubes homogeneously distributed therein to form a conductive path and at least two electrodes in electrical connection with the conductive path. Balloons and flexible elements used in medical procedures are particularly useful.

Claims

1. A flexible substrate having a major surface and a sensor attached to and aligned with the major surface of the substrate, wherein:

the sensor comprises an elastic body containing conductive nanotubes homogeneously distributed therein to form a conductive path and at least two electrodes in electrical connection with the conductive path, wherein the major surface is on an inflatable balloon having a conduit for transporting fluid into a cavity of the balloon to alter stress on the major surface of the inflatable balloon.

2. The substrate of claim 1 wherein presence of a nominally maximum fluid volume within the cavity maintains at least a 0.01 mm/m extension of a dimension in the elastic body of the sensor.

3. The substrate of claim 1 wherein the major surface comprises an elastomeric composition having a first modulus of elasticity and the elastic body of the sensor has a second modulus of elasticity and wherein the first modulus of elasticity is within 40% of the second modulus of elasticity.

4. The substrate of claim 2 wherein the major surface comprises an elastomeric composition having a first modulus of elasticity and the elastic body of the sensor has a second modulus of elasticity and wherein the first modulus of elasticity is within 40% of the second modulus of elasticity.

5. The substrate of claim 1 wherein the two electrodes of the sensor are in communication with both a power source and a processor.

6. The sensor of claim 1 wherein the sensor comprises an elastic body of a silicone rubber containing a loading of between 0.5% and 3%, by total weight of conductive nanotubes.

7. The substrate of claim 6 wherein at least two electrodes of the sensor are in communication with both a power source and a processor.

14. The substrate of claim 1 wherein the flexible substrate is an elastomeric composition having a first modulus of elasticity part of the major surface of the balloon and the elastic body of the sensor has a second modulus of elasticity and wherein the first modulus of elasticity is within 40% of the second modulus of elasticity.

15. The substrate of claim 2 wherein the flexible substrate is an elastomeric composition having a first modulus of elasticity part of the major surface of the balloon and the elastic body of the sensor has a second modulus of elasticity and wherein the first modulus of elasticity is within 25% of the second modulus of elasticity.

19. The substrate of claim 1 wherein the major surface comprises an interior surface of the balloon.

20. The substrate of claim 1 wherein the major surface comprises an exterior surface of the balloon.

8. A flexible substrate having a major surface and a sensor attached to and aligned with the major surface of the substrate, wherein:

the sensor comprises an elastic body containing conductive nanotubes homogeneously distributed therein to form a conductive path and at least two electrodes in electrical connection with the conductive path wherein the sensor comprises an elastic body of a silicone rubber containing a loading of between 0.5% and 3%, by total weight of conductive nanotubes, at least two electrodes of the sensor are in communication with both a power source and a processor, at least two electrodes of the sensor are in communication with both a power source and a processor and the major surface is on an inflatable balloon having a conduit for transporting fluid into a cavity of the balloon to alter stress on the major surface of the inflatable balloon.

9. The substrate of claim 8 wherein the major surface comprises an elastomeric composition having a first modulus of elasticity and the elastic body of the sensor has a second modulus of elasticity and wherein the first modulus of elasticity is within 40% of the second modulus of elasticity.

10. The substrate of claim 9 wherein the major surface is on an inflatable balloon having a conduit for transporting fluid into a cavity of the balloon to alter stress on the major surface of the inflatable balloon.

11. The substrate of claim 8 wherein the major surface is on an expandable balloon element in a medical device that applies localized pressure in a patient.

12. The substrate of claim 10 wherein the major surface is on an expandable balloon element in a medical device that applies localized pressure in a patient.

13. The substrate of claim 8 wherein the sensor comprises an electrically conductive silicone rubber composite comprised of a liquid silicone rubber with a multi-wall carbon nanotube loading of between 1%-3% by weight and a hardness between 10 and 60 Asker C hardness.

16. The substrate of claim 8 wherein the flexible substrate is an elastomeric composition having a first modulus of elasticity part of the major surface of the balloon and the elastic body of the sensor has a second modulus of elasticity and wherein the first modulus of elasticity is within 40% of the second modulus of elasticity.

17. The substrate of claim 9 wherein the flexible substrate is an elastomeric composition having a first modulus of elasticity part of the major surface of the balloon and the elastic body of the sensor has a second modulus of elasticity and wherein the first modulus of elasticity is within 40% of the second modulus of elasticity.

18. The substrate of claim 13 wherein the flexible substrate is an elastomeric composition having a first modulus of elasticity part of the major surface of the balloon and the elastic body of the sensor has a second modulus of elasticity and wherein the first modulus of elasticity is within 40% of the second modulus of elasticity.

21. A flexible substrate having a major surface and a sensor embedded in and aligned with the major surface of the substrate, wherein:

the sensor comprises an elastic body containing conductive nanotubes homogeneously distributed therein to form a conductive path and at least two electrodes in electrical connection with the conductive path wherein the sensor comprises an elastic body of a silicone rubber containing a loading of between 0.5% and 3%, by total weight of conductive nanotubes, at least two electrodes of the sensor are in communication with both a power source and a processor, at least two electrodes of the sensor are in communication with both a power source and a processor and the major surface is on an inflatable balloon having a conduit for transporting fluid into a cavity of the balloon to alter stress on the major surface of the inflatable balloon.