Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-8172995-B2
Publication Date
2012-05-08
Expiration Date
Abstract
An easily manufactured electrochemical test strip is made with facing electrode but side by side connectors for insertion into an electrochemical test meter. Current is conducted from the electrode on one layer to a connector on the other by a conductive layer disposed adjacent the end of a spacer layer, or by displacing the layer to bring a conductive surface on it into contact with the connector.
Core Innovation
The invention relates to an electrochemical test strip with facing electrodes in which the working electrode and counter electrode are provided on different substrates, while both electrode connectors are arranged on a single surface for insertion into an electrochemical test meter. The strip includes a base substrate that carries a first electrode and connector track and a second electrode connector, and a top layer carrying a second electrode and connector track that is positioned in opposition to an exposed portion of the first electrode and connector track.
The strip defines exposed portions of the electrode connector tracks by using a dielectric layer having two longitudinal strips separated by an open space, together with a spacer layer having two insulating strips separated by an open space. The open spaces expose portions of the first electrode connector and second electrode connector, with the exposed portion of the second electrode connector being greater in length than the exposed portion of the first electrode connector. A conductive material is disposed to make conductive contact with the exposed portion of the second electrode connector, and the top layer is shorter than the base substrate so that connector portions of the base substrate remain exposed.
In the documented variations, electrical connection is achieved with simplified structure compared with prior facing-electrode designs requiring through-holes and conductive fill, by providing an adjacent conductive material layer at the spacer/dielectric end or by displacing a top layer to bring a conductive surface into contact. Additional refinements include protective tape over connector ends, limiting reagent/liquid flow via a punched hole intersecting a capillary channel, and applying a hydrophobic coating near an electrode edge, including using conductive adhesives or conductive films. A small test cell volume is described as enabling small test volumes with glucose chemistries using glucose oxidase and redox mediators.
Claims Coverage
The independent claims define a layered test strip architecture with facing electrodes and exposed connector portions, where a conductive material couples an opposing connector portion and a shorter top layer maintains connector exposure. Across the independent claims, the inventive structure is realized by patterned dielectric/spacer layers exposing connector portions, conductive contact to the exposed second electrode connector, and a displaceable/short top layer arrangement, with additional structural and functional constraints in dependent variants.
Exposed connector portions defined by patterned dielectric and spacer layers
A base substrate has a dielectric layer comprising two strips of dielectric material extending longitudinally along the base substrate, where open space between the strips exposes a portion of the first electrode and connector track and extends less than the entire length of the base substrate; and a spacer layer comprising two strips of insulating material disposed over the dielectric layer, where open space between the insulating strips exposes inner longitudinal edges of the dielectric strips and extends less than the entire length such that the dielectric and insulating strips leave portions of the first electrode connector and the second electrode connector exposed, with the exposed portion of the second electrode connector being greater in length than the exposed portion of the first electrode connector.
Conductive contact to the exposed second electrode connector
A conductive material is disposed to make conductive contact with the exposed portion of the second electrode connector, where the top layer is configured so that a portion of the second electrode and connector track is disposed in opposition to the exposed portion of the first electrode and connector track, and a portion of the second connector track is disposed in contact with the conductive material.
Short top layer leaving exposed connector portion of the base substrate
A top layer comprising a substrate having disposed thereon a second electrode and connector track is shorter than the base substrate such that a connector portion of the base substrate having the exposed portions of the first electrode connector and the second electrode connector remains exposed.
Loop-form electrode and connector tracks with sized protective layer not fully covering the connector portion
The first electrode and connector track and the second electrode and connector track are each in the form of a loop with an extension forming the first electrode connector, and a protective layer adhered to the connector portion of the base substrate to the exterior surface of the top layer extends therebetween, the protective layer being sized such that the connector portion of the base substrate is not fully covered.
Conductive contact achieved by displaceable top layer pressed into the second electrode connector with protective-layer interaction
The conductive material disposed to make conductive contact with the second electrode connector is a part of the second electrode and connector track, and the top layer is displaceable to press the second electrode and connector track into conductive contact with the second electrode connector, where the top layer is displaced to press into conductive contact by a protective layer adhered to the connector portion of the base substrate to the exterior surface of the top layer and extending therebetween, the protective layer being sized such that the connector portion of the base substrate is not fully covered.
Across the independent claims, the inventive concept is a layered electrochemical test strip using dielectric and spacer layers that expose different-length connector portions, a conductive material establishing contact to the exposed second electrode connector, and a shorter top layer that leaves connector portions exposed. Further independent coverage specifies loop-form electrode/connector tracks with a protective layer that is sized not to fully cover the connector portion, and variations where the conductive contact is achieved by a displaceable top layer pressed into conductive contact.
Stated Advantages
Simplified manufacturing versus prior facing-electrode designs requiring through-holes and conductive fill.
Enables electrical connection using an adjacent conductive material layer at the spacer/dielectric end or by displacing the top layer to bring a conductive surface into contact.
Enables small test volumes, including small test cell volume (<1 μL) for glucose chemistries with glucose oxidase and redox mediator systems.
Documented Applications
Use as an electrochemical test strip for insertion into an electrochemical test meter (meter unit), including operation involving a strip port connector of a test meter.
Glucose electrochemical testing chemistry using glucose oxidase with redox mediators (e.g., ferrocyanide, osmium compound, or ruthenium compound) in a small test cell volume.
Interested in licensing this patent?