Abstract:
A body-mountable pyruvate sensing device includes an electrochemical sensor embedded in a polymeric material configured for mounting to a surface of an eye. The electrochemical sensor includes a working electrode, a reference electrode, and a reagent localized near the working electrode that selectively reacts with pyruvate. Application of a voltage between the working electrode and the reference electrode causes a current related to a concentration of pyruvate in a fluid to which the electrochemical sensor is exposed; the current is measured by the body-mountable device and wirelessly communicated.
Abstract:
A body-mountable urea sensing device includes an electrochemical sensor embedded in a polymeric material configured for mounting to a surface of an eye. The electrochemical sensor includes a working electrode, a reference electrode, and a reagent localized near the working electrode that selectively reacts with urea. A potentiometric voltage between the working electrode and the reference electrode is related to a concentration of urea in a fluid to which the electrochemical sensor is exposed; the voltage is measured by the body-mountable device and wirelessly communicated.
Abstract:
A method may involve: forming a sacrificial layer on a working substrate; forming a first bio-compatible layer on the sacrificial layer such that the first bio-compatible layer adheres to the sacrificial layer; forming a conductive pattern on the first bio-compatible layer; mounting an electronic component to the conductive pattern; forming a second bio-compatible layer over the first bio-compatible layer, the electronic component, and the conductive pattern; and removing the sacrificial layer to release the bio-compatible device from the working substrate. The first bio-compatible layer defines a first side of a bio-compatible device. The second bio-compatible layer defines a second side of the bio-compatible device.
Abstract:
Disclosed herein is a fluid conductivity sensor that can be used to obtain in-vivo measurements of conductivity of biological fluid samples, for example, to determine osmolarity. The conductivity sensor can be disposed on a substrate that is at least partially embedded within a polymeric material of a body-mountable device. The conductivity sensor can include a frame having a trench formed therein that defines a fluid sample cell. First and second electrodes can be formed on sidewalls of the trench, such that the first and second electrodes are on opposite sides of the fluid sample cell. A controller in the body-mountable device can operate the sensor by applying a voltage to the electrodes and measuring a current through a fluid occupying the fluid sample cell. The body-mountable device may indicate the current measurements wirelessly using an antenna.
Abstract:
An analyte sensor and a method for making the analyte sensor are disclosed. In one aspect, the analyte sensor includes a crosslinked, hydrophilic copolymer in contact with a surface of an electrode, and an analyte sensing component embedded within the crosslinked, hydrophilic copolymer. The method of making the analyte sensor includes depositing a precursor mixture containing monomers and an analyte sensing component onto an electrode, exposing the deposited precursor mixture to a controlled environment for a specified period of time, and photopolymerizing the deposited exposed precursor mixture into a copolymer layer in contact with a surface of the electrode. Exposing the deposited precursor mixture to a controlled environment can increase the sensitivity of the sensor by reducing the thickness of the copolymer layer and/or by causing the analyte sensitive component within the copolymer layer to have a non-uniform concentration within the layer.
Abstract:
An analyte sensor and method of making are provided. The analyte sensor includes a crosslinked, hydrophilic copolymer in contact with a surface of an electrode; and an analyte sensing component embedded within the crosslinked, hydrophilic copolymer, where the analyte sensing component is surrounded by a buffer having a predetermined buffering component and pH value and where the crosslinked, hydrophilic copolymer includes: backbone chains having first methacrylate-derived units, each having a first hydrophilic side chain; second methacrylate-derived units, each having a second hydrophilic side chain, where the first and second side chains are the same or different; third methacrylate-derived units; and hydrophilic crosslinks between third methacrylate-derived units in different backbone chains. The analyte sensor may be maintained at a humidity level of less than 25% to maintain its performance during storage.
Abstract:
A method may involve forming one or more photoresist layers over a sensor located on a structure, such that the sensor is covered by the one or more photoresist layers. The sensor is configured to detect an analyte. The method may involve forming a first polymer layer. Further, the method may involve positioning the structure on the first polymer layer. Still further, the method may involve forming a second polymer layer over the first polymer layer and the structure, such that the structure is fully enclosed by the first polymer layer, the second polymer layer, and the one or more photoresist layers. The method may also involve removing the one or more photoresist layers to form a channel through the second polymer layer, wherein the sensor is configured to receive the analyte via the channel.
Abstract:
A body-mountable pyruvate sensing device includes an electrochemical sensor embedded in a polymeric material configured for mounting to a surface of an eye. The electrochemical sensor includes a working electrode, a reference electrode, and a reagent localized near the working electrode that selectively reacts with pyruvate. Application of a voltage between the working electrode and the reference electrode causes a current related to a concentration of pyruvate in a fluid to which the electrochemical sensor is exposed; the current is measured by the body-mountable device and wirelessly communicated.
Abstract:
An analyte sensor for the continuous or semi-continuous monitoring of physiological parameters and a method for making the analyte sensor are disclosed. The analyte sensor includes a crosslinked copolymer network in contact with a surface of an electrode. The copolymer network has voids formed by the removal of a porogen, and an analyte sensing component is immobilized within the network. The method involves forming a solution of the precursors of the copolymer, depositing the mixture on a surface of an electrode, and curing the deposited mixture to provide the analyte sensor.
Abstract:
An analyte sensor and a method for making the analyte sensor are disclosed. In one aspect, the analyte sensor includes a sensing membrane having a crosslinked network with an embedded analyte sensing component. In another aspect, the analyte sensor includes a protective membrane adjacent to the surface of the sensing membrane. The protective membrane can be a crosslinked, hydrophilic copolymer having methacrylate-derived backbone chains of first methacrylate-derived units, second methacrylate-derived units and third methacrylate-derived units. The first and second methacrylate-derived units have hydrophilic side chains, and the third methacrylate-derived units in different backbone chains are connected by hydrophilic crosslinks. A method for making the analyte sensor is also disclosed.