METHOD FOR MANUFACTURING A SENSOR BASE PLATE FOR AN IN VIVO ANALYTE SENSING DEVICE

Abstract

This disclosure relates to a method of manufacturing an in vivo analyte sensing device, which is adapted for detecting at least one analyte in a body fluid or tissue and an in vivo analyte sensing device obtainable by said manufacturing method. Further, this disclosure relates to a method of manufacturing a sensor base plate and a sensor base plate obtainable by said manufacturing method. The sensor base plate may be used for the manufacture of an in vivo analyte sensing device.

Claims

1. A method of manufacturing an in vivo analyte sensor assembly, comprising: (a) providing a sensor base plate having a recess with an elastomeric conductive polymer disposed in the recess, the elastomeric conductive polymer being retained in the recess without externally added adhesive and/or without deformation; (b) fitting a sensor with the sensor base plate, wherein the sensor comprises a first sensor contact pad on a first side of the sensor and a second sensor contact pad on a second side of the sensor, wherein the first and second sides oppose each other and the first sensor contact pad is placed into electrical contact with the elastomeric conductive polymer; (c) connecting an electronics unit with the first sensor contact pad and the second sensor contact pad; and (d) positioning a cover over the sensor base plate and the electronics unit.

2. The method of claim 1, wherein the analyte is glucose.

3. The method of claim 1, wherein step (a) comprises: (a1) providing a raw sensor base plate with the recess, and (a2) passing a curable conductive polymer composition into the recess and curing the curable conductive polymer composition, wherein the elastomeric conductive polymer is formed within the recess and wherein the sensor base plate is obtained.

4. The method of claim 3, wherein steps (a1) and (a2) are performed as an integrated process carried out in a single manufacturing device.

5. The method of claim 4, wherein the sensor base plate is manufactured by two-component molding, wherein in a first step the raw sensor base plate is manufactured by passing a curable sensor plate polymer composition into a mold and forming the raw sensor base plate by curing the curable sensor plate polymer composition in the mold, and wherein in a second step the elastomeric conductive polymer is formed in the recess while the raw sensor base plate is still in the mold.

6. The method of claim 3, wherein the manufacturing process comprises passing the curable conductive polymer composition into the recess through a passage extending through the raw sensor base plate, wherein a mold is placed over an open side of the recess and wherein the surfaces of the mold and the recess define a cavity for the curable conductive polymer composition, wherein after passing the curable conductive polymer composition into the cavity and curing, the surface of the mold defines an outward surface of the elastomeric conductive polymer, wherein the outward surface is distal from the sensor base plate.

7. The method of claim 1, wherein the sensor is a two-electrode sensor and wherein the first and the second sensor contact pads are connected to different electrodes of the sensor.

8. The method of claim 1, wherein the sensor comprises at least one working electrode, which is specific for the analyte to be detected, and wherein the sensor comprises a further electrode selected from the group consisting of a counter electrode, a reference electrode and a combined counter/reference electrode.

9. The method of claim 1, wherein the second sensor contact pad is not in contact with the elastomeric conductive polymer.

10. An in vivo analyte sensor assembly, comprising: a sensor base plate having a recess with an elastomeric conductive polymer disposed in the recess, the elastomeric conductive polymer being retained in the recess without externally added adhesive and/or without deformation; a sensor fitted with the base plate, the sensor comprising a first sensor portion adapted to be inserted into a user's body and a second sensor portion adapted to be outside the user's body; a first sensor contact pad disposed on a first side of the sensor and a second sensor contact pad disposed on a second side of the sensor, wherein the first side and the second side oppose each other and the first sensor contact pad is placed into electrical contact with the elastomeric conductive polymer; an electronics unit connected to the first sensor contact pad and the second sensor contact pad; and a cover positioned over the sensor base plate and the electronics unit.

11. A method of manufacturing a sensor base plate adapted for an in vivo analyte sensing device, the method comprising the steps: (a1) providing a raw sensor base plate comprising a recess, and (a2) passing a curable conductive polymer composition into the recess and curing the curable conductive polymer composition, wherein an elastomeric conductive polymer is formed within the recess and wherein the sensor base plate is obtained.

12. The method of claim 11, wherein steps (a1) and (a2) are performed as an integrated process carried out in a single manufacturing device.

13. The method of claim 12, wherein the sensor base plate is manufactured by two-component molding, wherein in a first step, the raw sensor base plate is manufactured by passing a curable sensor plate polymer composition into a mold and forming the raw sensor base plate by curing the curable sensor plate polymer composition in the mold, and wherein in a second step, the elastomeric conductive polymer is formed in the recess of the raw sensor base plate while the raw sensor base plate is still in the mold.

14. The method of claim 11, wherein step (a2) comprises passing the curable conductive polymer composition into the recess through an passage extending through the raw sensor base plate, wherein a mold is placed over the open side of the recess, and wherein the surfaces of the mold and the recess define a cavity for the curable conductive polymer composition, wherein after passing the curable conductive polymer composition into the cavity and curing, the surface of the mold defines an outward surface of the elastomeric conductive polymer, wherein the outward surface is distal from the sensor base plate.

15. A sensor base plate, comprising a recess, wherein at least one elastomeric conductive polymer is present in the recess and is retained in the recess without externally added adhesive and/or without deformation of its shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0072] The above-mentioned aspects of exemplary embodiments will become more apparent and will be better understood by reference to the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0073] FIG. 1 schematically depicts a sensing device having a sensor contacting an electronics unit via an electrically conductive rubber sponge; and

[0074] FIG. 2 schematically depicts another embodiment of a sending device having a sensor contacting an electronics unit via a flexibly electrically conductive element.

DESCRIPTION

[0075] The embodiments described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of this disclosure.

[0076] FIG. 1 schematically depicts a prior art sensing device comprising a sensor contacting an electronics unit via a flexible electrically conductive rubber sponge element. The sensing device comprises a sensor base plate (10) having a recess (12). Within the recess (12), a cut piece of conductive rubber sponge (14) is inserted. A sensor (16) is inserted on top of the conductive rubber sponge (14), which thereby is deformed. The upper and lower sides of the sensor may be coated with a conductive material such as a metal, e.g., gold layer (18a, 18b). The gold layer on the lower side (18a) forms a first sensor contact pad, which is in electrical contact with the deformed rubber sponge (14). On the other side, i.e., the upper side, the gold layer (18b) is overlaid with a non-conductive layer, e.g., photo resist (20). A part of the gold layer (18b) of the upper side is left open forming the second sensor contact pad which may contact the second contact site of the electronics unit (not shown). Further, due to the deformation of the rubber sponge (14), voids (22a, 22b) are present. The sensor (16) is aligned with an electronics unit (24) comprising a printed circuit board (PCB) or a printed circuit board assembly (PCBA). A part of the electronics unit (24) is coated with a non-conductive layer, e.g., photo resist (26) and a further part of the electronics unit (16) is coated with a conductive layer (28), e.g., a metal such as gold. An electrical contact between sensor contact pad (18a) and the first contact site (28) on the electronics unit (24) is provided via the deformed rubber sponge (14) as shown by an arrow (30).

[0077] The use of a cut piece of a rubber sponge (14) is however associated with substantial difficulties as indicated supra. Replacement of sponge rubber element (14) by an elastomeric conductive polymer, which has been formed in situ within the recess (12) and is thereby retained within the recess, e.g., by adhering to its surface without externally added adhesive and/or by physical retention without deformation of its shape, can overcome these problems.

[0078] FIG. 2 schematically depicts an embodiment of this disclosure, wherein an elastomeric polymer conductive element is formed in a recess of a raw sensor base plate by injection molding through the sensor base plate. A raw sensor base plate (40) is provided comprising at least one recess (42). A passage (44) extends between openings (44a, 44b) through the sensor base plate (40) to the recess (42). The passage can be provided during and/or after the manufacturing of the raw sensor base plate, e.g., by using an appropriate mold and/or by drilling. A mold (46), e.g., an injection mold is provided for covering the outer surface of recess (42) thereby forming a cavity defined by the surfaces of the mold (46) and the recess (42). A curable elastomeric polymer composition (48) is passed through the passage (44) from opening (44a) to opening (44b) and then into the cavity defined by the recess (42) and the mold (46). Subsequently, the composition (48) is cured in situ within the cavity. Thereby, an elastomeric conductive polymer element is obtained. The outward surface of the elastomeric conductive polymer element, i.e., the surface distal from the recess (42) is defined by the surface of the mold (46). Thus, an elastomeric conductive polymer element having a well-defined surface with a three-dimensional shape, e.g., a structure (50) including a recess for receiving a sensor (not shown) is provided.

[0079] Further, this disclosure is described without any limitation by the following embodiments of the specification.

[0080] Embodiment 1: A method of manufacturing an in vivo analyte sensing device, the method comprising the steps: [0081] (a) providing a sensor base plate comprising at least one recess, wherein at least one elastomeric conductive polymer element is present in the at least one recess, [0082] (b) fitting a sensor with the sensor base plate wherein the sensor comprises: [0083] (i) a first sensor contact pad on a first side of the sensor, and [0084] (ii) a second sensor contact pad on a second side of the sensor, wherein the first side and the second side are different and particularly opposing each other,  and wherein the first sensor contact pad is placed into electrical contact with the at least one elastomeric conductive polymer element; [0085] (c) connecting an electronics unit with the first sensor contact pad and the second sensor contact pad, and [0086] (d) positioning a cover over the sensor base plate and the electronic unit.

[0087] Embodiment 2: The method of Embodiment 1, wherein in step (a) the at least one elastomeric conductive polymer element is retained in the at least one recess without externally added adhesive and/or without deformation of its shape.

[0088] Embodiment 3: The method of Embodiments 1 or 2, wherein the analyte is selected from glucose, cholesterol, triglycerides, and lactate.

[0089] Embodiment 4: The method of any one of Embodiments 1-3, wherein the analyte is glucose.

[0090] Embodiment 5: The method of any one of Embodiments 1-4, wherein step (a) comprises: [0091] (a1) providing a raw sensor base plate comprising at least one recess, and [0092] (a2) passing, e.g., injecting a curable conductive polymer composition into the at least one recess of the raw sensor base plate and curing the curable conductive polymer composition wherein the at least one elastomeric conductive polymer element is formed within the at least one recess and wherein the sensor base plate is obtained.

[0093] Embodiment 6: The method of Embodiment 5, wherein steps (a1) and (a2) are performed as an integrated process, which is carried out in a single manufacturing device.

[0094] Embodiment 7: The method of Embodiment 6, wherein the sensor base plate is manufactured by two-component molding, e.g., two-component injection molding, wherein in a first step, the raw sensor plate is manufactured by passing, e.g., injecting, a curable sensor plate polymer composition into a mold and forming the raw sensor base plate by curing the curable sensor plate polymer composition in the mold, and wherein in a second step, the at least one elastomeric conductive polymer element is formed in the at least one recess of the raw sensor base plate while the raw sensor base plate is still in the mold.

[0095] Embodiment 8: The method of any one of Embodiments 5-7, wherein the manufacturing process comprises passing, e.g., injecting the curable conductive polymer composition into the at least one recess through a passage extending through the raw sensor base plate.

[0096] Embodiment 9: The method of Embodiment 8, wherein a mold is placed over the open side of the recess, wherein the surfaces of the mold and the recess define a cavity for the curable conductive polymer composition, wherein after passing the curable conductive polymer composition into the cavity and curing, the surface of the mold defines an outward surface of the elastomeric conductive polymer element, wherein the outward surface is distal from the sensor base plate.

[0097] Embodiment 10: The method of any one of Embodiments 1-9, wherein the raw sensor base plate comprises and preferably consists of a non-conductive material, particularly of a non-conductive polymer.

[0098] Embodiment 11: The method of any one of Embodiments 1-10, wherein the raw sensor base plate comprises and preferably consists of a thermoplastic polymer, particularly of a substantially rigid thermoplastic polymer.

[0099] Embodiment 12: The method of any one of Embodiments 1-11, wherein the at least one elastomeric conductive polymer element comprises an elastomeric polymer selected from a polyolefin-based polymer such as polyethylene or polypropylene, a polystyrene-based polymer, a polyurethane or polyurea-based polymer, a poly(meth)acrylic-based polymer such as acrylonitrile, a polyacrylate or a polymethacrylate, or an acrylonitrile-butadiene-styrene copolymer or any mixture thereof.

[0100] Embodiment 13: The method of any one of Embodiments 1-12, wherein the at least one elastomeric conductive polymer element comprises a conductive additive, e.g., conductive fibers and/or particles, particularly selected from carbon fibers and/or particles, metal fibers and/or particles and metal-coated carbon fibers and/or particles.

[0101] Embodiment 14: The method of any one of Embodiments 1-13, wherein the sensor is a two-electrode sensor.

[0102] Embodiment 15: The method of any one of Embodiments 1-14, wherein the sensor comprises at least one working electrode, which is specific for the analyte to be detected.

[0103] Embodiment 16: The method of any one of Embodiments 1-15, wherein the sensor comprises at least one working electrode and at least one further electrode, wherein the at least one further electrode is selected from the group consisting of at least one counter electrode, at least one reference electrode and at least one combined counter/reference electrode.

[0104] Embodiment 17: The method of any one of Embodiments 1-16, wherein the first and the second sensor contact pads are connected to different electrodes of the sensor, particularly wherein the first sensor contact pad is connected to a working electrode and the second sensor contact pad is connected to at least one further electrode or vice versa.

[0105] Embodiment 18: The method of any one of Embodiments 1-17, wherein the second sensor contact pad is not in contact with the elastomeric conductive polymer.

[0106] Embodiment 19: The method of any one of Embodiments 1-18, wherein the second sensor contact pad is in direct electrical contact with the electronics unit, wherein the electrical contact between the first sensor contact pad and the electronics unit is electrically separated from the electrical contact between the second sensor pad and the electronics unit.

[0107] Embodiment 20: An in vivo analyte sensing device obtainable by a method of any one of Embodiments 1-19.

[0108] Embodiment 21: An in vivo analyte sensing device, particularly obtainable by a method of any one of Embodiments 1-20 comprising: [0109] a) a sensor base plate comprising at least one recess, wherein at least one elastomeric conductive polymer element is present in the at least one recess and wherein the at least one elastomeric conductive polymer element is retained in the at least one recess without externally added adhesive and/or without deformation of its shape, [0110] (b) a sensor comprising a first portion adapted to be inserted into a user's body and a second sensor portion adapted to be outside the user's body, which is fitted with the sensor base plate, wherein the second sensor portion comprises: [0111] (i) a first sensor contact pad on a first side of the second sensor portion, and [0112] (ii) a second sensor contact pad on a second side of the second sensor portion, wherein the first side and the second side are different, particularly opposing each other,  wherein the first sensor contact pad is in electrical contact with the at least one elastomeric conductive polymer element; [0113] (c) an electronics unit connected with the first sensor contact pad and the second sensor contact pad wherein the at least one conductive polymer element is in electrical contact with the electronics unit and [0114] (d) a cover.

[0115] Embodiment 22: The sensing device of Embodiments 20 or 21 further comprising at least one of [0116] (e) an electrical power unit, and [0117] (f) a fastening element adapted for fasting the device to the user's body.

[0118] Embodiment 23: The sensing device of any one of Embodiments 20-22, wherein the at least one elastomeric conductive polymer element is retained in the at least one recess by adhering to the surface of the at least one recess without externally added adhesive.

[0119] Embodiment 24: The sensing device of any one of Embodiments 20-22, wherein the at least one elastomeric conductive polymer element is retained in the at least one recess by physical retention without deformation of its shape.

[0120] Embodiment 25: A method of measuring an analyte in vivo, comprising using a sensing device of any one of Embodiments 20-24.

[0121] Embodiment 26: A method of manufacturing a sensor base plate adapted for an in vivo analyte sensing device, the method comprising the steps: [0122] (a1) providing a raw sensor base plate comprising at least one recess, and [0123] (a2) passing, e.g., injecting, a curable conductive polymer composition into the at least one recess of the raw sensor base plate and curing the curable conductive polymer composition wherein at least one elastomeric conductive polymer element is formed within the at least one recess and wherein the sensor base plate is obtained.

[0124] Embodiment 27: The method of Embodiment 26, wherein the curable conductive polymer composition is passed, e.g., injected, into the at least one recess in a free-dose manner or in the presence of a mold.

[0125] Embodiment 28: The method of Embodiments 26 or 27, wherein step (a1) comprises forming the raw sensor base plate body by injection-molding.

[0126] Embodiment 29: The method of any one of Embodiments 26-28, wherein steps (a1) and (a2) are performed as an integrated process, which is carried out in a single manufacturing device.

[0127] Embodiment 30: The method of Embodiment 29, wherein the sensor base plate is manufactured by two-component molding, e.g., two-component injection molding, wherein in a first step, the raw sensor plate is manufactured by passing, e.g., injecting, a curable sensor plate polymer composition into a mold and forming the raw sensor base plate by curing the curable sensor plate polymer composition in the mold, and wherein in a second step, the at least one elastomeric conductive polymer element is formed in the at least one recess of the raw sensor base plate while the raw sensor base plate is still in the mold.

[0128] Embodiment 31: The method of any one of Embodiments 26-30, wherein step (a2) comprises passing, e.g., injecting the curable conductive polymer composition into the at least one recess through a passage extending through the raw sensor base plate.

[0129] Embodiment 32: The method of Embodiment 31, wherein a mold is placed over the open side of the recess, and wherein the surfaces of the mold and the recess define a cavity for the curable conductive polymer composition, wherein after passing the curable conductive polymer composition into the cavity and curing, the surface of the mold defines an outward surface of the elastomeric conductive polymer element, wherein the outward surface is distal from the sensor base plate.

[0130] Embodiment 33: A sensor base plate obtainable by the method of any one of Embodiments 26-32.

[0131] Embodiment 34: A sensor base plate adapted for an in vivo analyte sensing device, particularly obtainable by the method of any one of Embodiments 26-32, comprising a raw sensor base plate comprising at least one recess, wherein at least one elastomeric conductive polymer element is present in the at least one recess and wherein the at least one elastomeric conductive polymer element is retained in the at least one recess without externally added adhesive and/or without deformation of its shape.

[0132] Embodiment 35: The sensor base plate of Embodiment 34, wherein the at least one elastomeric conductive polymer element is retained in the at least one recess by adhering to the surface of the at least one recess without externally added adhesive.

[0133] Embodiment 36: The sensor base plate of Embodiment 34, wherein the at least one elastomeric conductive polymer element is retained in the at least one recess by physical retention without deformation of its shape.

[0134] Embodiment 37: Use of the sensor base plate of any one of Embodiments 33-36 for the manufacture of an in vivo analyte sensor.

[0135] While exemplary embodiments have been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of this disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.