Electrochemical Sensor With Small Openings and Ion-Blocking Membrane
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Solution Overview
Problem
Existing electrochemical sensors for sensing analytes are slow, fragile, bulky, flow-dependent, unstable, and difficult to manufacture, with high baseline drift and low sensitivity.
Innovation Solution
A microfabricated electrochemical sensor with small analyte permeable openings, a chamber containing an electrolyte, and a non-ionic membrane that separates the associated volume from the chamber, ensuring a distance of 25 micrometers or less from any point in the opening to the wall, with a cross-sectional area of 2500 square micrometers or less, and incorporating a guard electrode for stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional electrochemical sensors are used, then analyte detection is achieved, but response time is slow and baseline drift is high
Solution Approach 1:
The sensor is divided into multiple solid elements (first solid element, second solid element, third solid element) with a chamber positioned between them. This segmentation allows for optimized analyte transport paths and improved response time while maintaining stability through the distributed structure.
Solution Approach 2:
Different regions of the sensor have specialized functions: the chamber contains electrolyte for ionic conduction, the working electrode detects analyte, the reference electrode provides stable potential, and the membrane selectively permits analyte passage. This local specialization optimizes each region's performance for its specific function.
2Strength
If conventional sensor structures are used, then analyte sensing is possible, but the sensor is fragile and bulky
Solution Approach 1:
The sensor employs thin-film solid elements and a membrane structure that provides mechanical strength while maintaining a compact form factor. The membrane acts as a selective barrier while the thin-film construction reduces overall sensor size and fragility.
Solution Approach 2:
The chamber is positioned between solid elements in a nested arrangement, with the working electrode, reference electrode, and membrane contained within the chamber structure. This nested configuration minimizes sensor volume while maintaining all necessary functional components.
3Ease of manufacture
If conventional sensor designs are used, then analyte detection is achieved, but manufacturing complexity is high
Solution Approach 1:
The sensor is constructed from discrete solid elements that can be manufactured separately and then assembled. This segmentation simplifies manufacturing by allowing each element to be optimized and produced using standard fabrication techniques before final assembly.
Solution Approach 2:
The solid elements serve multiple functions: providing structural support, containing electrodes, facilitating analyte transport, and enabling electrical connections. This multi-functionality reduces the number of separate components needed, simplifying manufacturing.
4Measurement precision
If conventional sensor configurations are used, then analyte measurement is possible, but sensitivity is low and flow dependence is high
Solution Approach 1:
The membrane is positioned at a specific location to optimize analyte transport to the working electrode, creating a localized high-sensitivity region. The chamber geometry and electrode placement are optimized locally to maximize analyte detection efficiency while minimizing flow dependence.
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 sensor achieves rapid response times, mechanical robustness, low stirring sensitivity, and improved manufacturing tolerances, while maintaining ionic composition and reducing false-positive signals, enabling precise analyte detection.
Implementation Method 1
an analyte permeable membrane (124) in said one or more analyte permeable openings, such as a silicone membrane, such as a membrane which enables separating liquids (such as aqueous solutions) on either side of the one or more analyte permeable openings, wherein the membrane is not permeable to ions
Implementation Method 2
said one or more analyte permeable openings forming a diffusion barrier between the associated volume and the chamber
Implementation Method 3
a distance from any point in at least one cross-sectional plane to the nearest point of a wall of said opening is 25 micrometer or less, where said cross-sectional plane is orthogonal to a direction of movement of an analyte diffusing from the associated volume to the working electrode along the shortest possible path
Data Source
Figure 1A~2
Figure 3~5
Figure 6~8
AI summary
A electrochemical sensor (100) for sensing an analyte in an associated volume (106), the sensor comprising a first solid element (126), a second solid element (128) being joined to the first solid element, a chamber (110) being placed at least partially between the first solid element and the second solid element, a working electrode (104) in the chamber (110) and wherein one or more analyte permeable openings (122) connect the chamber with the associated volume (106) and wherein the electrochemical sensor (100) further comprises an analyte permeable membrane (124) in said one or more analyte permeable openings, and wherein the one or more analyte permeable openings are arranged so that a distance from any point in at least one cross-sectional plane to the nearest point of a wall of said opening is 25 micrometer or less.