Analyte Sensor with Overlapping Silver Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing analyte sensors for measuring body fluids face challenges in long-term stability, biocompatibility, and manufacturing efficiency, particularly due to the limited lifespan of Ag/AgCl reference electrodes and the complexity of precise surface area control for effective analyte detection.
Innovation Solution
An analyte sensor design featuring a substrate with a working electrode and a second electrode comprising overlapping silver layers with different compositions, a hydrophobic polymer membrane, and a simplified manufacturing process that reduces the number of electrodes from three to two, enhancing biocompatibility and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a three-electrode system with Ag/AgCl reference electrode is used, then analyte measurement capability is achieved, but sensor lifetime is limited due to AgCl dissolution
Solution Approach 1:
The patent removes the Ag/AgCl reference electrode from the sensor system entirely, extracting the problematic component that causes AgCl dissolution. The sensor operates as a two-electrode system with only a working electrode and counter electrode, eliminating the source of harmful AgCl dissolution while maintaining analyte measurement capability through alternative reference potential establishment.
Solution Approach 2:
The counter electrode serves multiple functions: it acts as both the counter electrode for current flow and provides the reference potential function traditionally performed by a separate reference electrode. This multi-functionality reduces the number of components needed while maintaining measurement capability.
2Productivity
If screen printing method is used for electrode fabrication, then manufacturing efficiency is improved, but manufacturing precision deteriorates due to difficulty in controlling exposed Ag/AgCl surface area
Solution Approach 1:
By removing the Ag/AgCl reference electrode entirely from the design, the patent eliminates the need to control its exposed surface area. The screen printing process is applied only to the working and counter electrodes where surface area control is less critical, thereby maintaining manufacturing efficiency while avoiding the precision problems associated with Ag/AgCl area control.
3Reliability
If Ag/AgCl reference electrode is used, then electrochemical measurement function is achieved, but biocompatibility worsens due to inflammation reaction
Solution Approach 1:
The patent extracts and removes the Ag/AgCl reference electrode that causes inflammation reactions. By eliminating this component, the sensor's biocompatibility is improved while measurement function is maintained through the two-electrode configuration where the counter electrode provides both counter and reference functions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution results in a cost-efficient, stable, and biocompatible analyte sensor with improved long-term performance and reduced manufacturing complexity, allowing for effective analyte detection with extended sensor lifespan.
Implementation Method 1
enzyme molecules are bound which release charge carriers by catalytic conversion of the analyte molecules. In this process, an electrical current is generated as a measuring signal
Implementation Method 2
the sensitivity is often tailored by using diffusion limiting membranes
Implementation Method 3
the reference electrode is typically composed of Ag/AgCl, which is fabricated via screen printing or electroplating
Implementation Method 4
membranes excluding particular compounds in order to allow access to the actual sensing sites only for low molecular weight compounds
Data Source
AI summary
The disclosure relates to an analyte sensor comprising a substrate, at least one working electrode, at least one second electrode and a membrane, wherein the membrane is located on top of the second electrode, and the second electrode has at least one first silver layer and at least one second silver layer which at least partially overlap with one another and have different compositions. The sensor includes at least one exposed area of the first silver layer disposed on the exterior of the sensor to provide for direct contact with body fluid when implanted. The disclosure further relates to a process for manufacturing an analyte sensor.