Sensors with subminiature through holes
First Claim
1. A sensor for use in a fluid analyte analyzer, including:
- an electrically insulating substrate defined by at least one planar surface;
a subminiature through hole having a diameter between about 0.002 to about 0.006 inch which traverses the substrate, said subminiature through hole being filled with a conductive material; and
a sensor electrode having a diameter between about 0.046 to about 0.078 inch formed on the planar surface over the subminiature through hole, wherein the conductive material disposed within said subminiature through hole is compatible with the material from which the sensor electrode is made and taken from the group consisting of silver, silver/platinum, and alloys of silver and platinum.
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Accused Products
Abstract
The present invention is a sensor having an electrode formed in electrical contact with a subminiature through hole. Because of the small diameter of the through hole, the material that fills the through hole and the through hole itself have an essentially negligible effect on the sensor. A relatively large number of sensors can be formed on the surface of the substrate within a relatively small fluid flowcell. Thus, more information can be attained using less analyte. The sensors of the present invention are preferably disposed on an alumina substrate which is essentially impervious to aqueous electrolytes and blood over long periods of storage in potentially corrosive environments. Since the substrate on which the sensors are deposited, and the encapsulants which insulate the conductive elements of the sensor do not break down or become unstable when exposed over time to such corrosive environments, the isolation that is provided remains very high between each sensor and each other sensor, between each sensor and each conduction path, and between each conduction path and each other conduction path. The superior isolation provides for a high level of accuracy in the sensor of the present invention. Furthermore, the use of the through holes allows the conduction paths between the electrodes of the sensors and any external devices to be exclusively on the opposite side of the substrate from the sample. This physical isolation of the sample from the conduction paths between the sensor electrodes and external devices ensures very high electrical isolation between each of the sensors is maintained over an extended period time during which reactive fluids (such as electrolytes and/or blood) are present in the flowcell.
119 Citations
60 Claims
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1. A sensor for use in a fluid analyte analyzer, including:
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an electrically insulating substrate defined by at least one planar surface; a subminiature through hole having a diameter between about 0.002 to about 0.006 inch which traverses the substrate, said subminiature through hole being filled with a conductive material; and a sensor electrode having a diameter between about 0.046 to about 0.078 inch formed on the planar surface over the subminiature through hole, wherein the conductive material disposed within said subminiature through hole is compatible with the material from which the sensor electrode is made and taken from the group consisting of silver, silver/platinum, and alloys of silver and platinum. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A potentiometric sensor for analyzing fluid samples, the sensor including:
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a substrate defined by at least one planar surface; a subminiature through hole having a diameter between about 0.002 to about 0.006 inch through the substrate, said subminiature through hole being filled with a conductive material; a first metallic sensor electrode having a diameter between about 0.046 to about 0.078 inch formed upon the planar surface of the substrate over the subminiature through hole, wherein the conductive material disposed within said subminiature through holes is compatible with the material from which the sensor electrode is made and taken from the group consisting of silver, silver/platinum, and alloys of silver and platinum; a first polymeric layer deposited on the substrate about the metallic sensor electrode defining a lower sensor cavity; a second polymeric layer deposited on the first polymeric layer, the second polymeric layer defining an upper sensor cavity, the area of horizontal cross sections of the upper sensor cavity being greater than the area of horizontal cross sections of the lower sensor cavity; an electrolyte solution containing ions of inorganic salts that disassociate in solution; and a membrane for trapping the electrolyte solution against the electrode. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53)
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54. A plurality of sensors formed on a planar surface of a substrate, each sensor being formed in close proximity to at least one other sensor, each sensor including:
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a subminiature through hole having a diameter between about 0.002 to about 0.006 inch through the substrate, said subminiature through hole being filled with a conductive material; a first sensor electrode having a diameter between about 0.046 to about 0.078 inch formed upon the planar surface of the substrate over the subminiature through hole, wherein the conductive material disposed within said subminiature through holes is compatible with the material from which the sensor electrode is made and taken from the group consisting of silver, silver/platinum and alloys of silver and platinum; a first polymeric layer deposited on the substrate about the metallic sensor electrode defining a lower sensor cavity; a second polymeric layer deposited on the first polymeric layer, the second polymeric layer defining an upper sensor cavity, the area of horizontal cross sections of the upper sensor cavity being greater than the area of horizontal cross sections of the lower sensor cavity; an electrolyte solution containing ions of inorganic salts that disassociate in solution; and a selectively permeable membrane for trapping the electrolyte solution against the electrode. - View Dependent Claims (55, 56, 57, 58, 59, 60)
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Specification