Flexible electrically conductive nanotube sensor for elastomeric devices
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.
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.
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.
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.
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.
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.
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.