Biosensor Reagent Diffusion Control via Rounded Corners

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Solution Overview

Problem

Existing biosensors face challenges in accurately controlling the uniformity of reaction reagent thickness on electrodes, leading to inconsistent test results due to edge effects and surface tension, which affects the precision of glucose concentration detection in blood samples.

Innovation Solution

The use of a non-sharp-angled reagent diffusion control zone and assisted diffusion electrodes ensures even distribution of reaction reagents, covering the entire active region without overflow, with the insulating layer thickness ranging from 1-50 micrometers, primarily 3-30 micrometers, to maintain uniformity and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If reaction reagents are dropped onto the electrode using a rectangle reagent-diffusion control zone, then the reagents are limited to the required area, but the reagents cannot fully cover the whole rectangle zone especially at the four vertex angles, leading to non-uniform thickness

Engineering Contradiction:
Improveamount of reaction reagentVSAvoiduniformity of reagent thickness
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent changes the reagent diffusion control zone from a rectangular shape with sharp angles to a shape with rounded corners or circular arcs. This curvature modification eliminates the vertex angle problem where reagents fail to cover, allowing uniform reagent distribution across the entire control zone while maintaining precise quantity control.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Reliability

If the insulating layer thickness is increased to prevent reagent overflow, then reagent containment improves, but the uniformity of reagent thickness decreases due to surface tension effects

Engineering Contradiction:
Improvereagent containmentVSAvoiduniformity of reagent thickness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

By rounding the corners of the reagent diffusion control zone, the patent eliminates sharp edges where surface tension causes reagent accumulation or overflow. The curved geometry allows capillary forces to distribute reagents uniformly across the zone, achieving both containment and uniformity simultaneously.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Loss of substance

If the sample channel size is reduced to minimize reagent用量, then reagent consumption decreases, but the accuracy of glucose concentration detection decreases due to insufficient reagent coverage

Engineering Contradiction:
Improvereagent consumptionVSAvoidaccuracy of glucose concentration detection
Core Design Contradiction:
Loss of substanceVSMeasurement precision

Solution Approach 1:

The rounded corner design maximizes the effective reagent coverage area within the sample channel by eliminating dead zones at sharp angles. This ensures complete reagent coverage of the electrode surface, maintaining detection accuracy while minimizing the overall channel size and reagent consumption.

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Ease of manufacture

If traditional rectangle reagent diffusion control zone is used, then manufacturing process is simple, but products produced at the same batch have different reaction reagent-covered areas, leading to inaccurate test results

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidaccuracy of test results
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent modifies the rectangle control zone to have rounded corners, which can be easily implemented in existing manufacturing processes through standard photolithography and etching techniques. This geometric modification ensures consistent reagent coverage across all products in a batch, improving test result accuracy without significantly complicating the manufacturing process.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

This approach enhances the uniformity of reaction reagent thickness, improving the accuracy of glucose concentration detection and reducing inconsistencies across biosensors produced in the same batch, leading to more reliable testing results.

Implementation Method 1

the reaction reagent in the channel reacts with the analyte in the sample thereby producing detectable signals

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

The insulating layer has a thickness of 1-50 micrometers, preferably 3-30 micrometers, and the reaction reagent diffusion control zone has a non-sharp-angled closed boundary

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Data Source

PatentEP2980572B1Biosensor and method for manufacturing a biosensor
Publication Date: 2023.08.16 LEADWAY HK
  • EP2980572B1 patent drawingFigure 1
  • EP2980572B1 patent drawingFigure 2A~2E
  • EP2980572B1 patent drawingFigure 3~4

AI summary

A biosensor and a method for manufacturing the biosensor. The biosensor comprises an insulative substrate (1), an electrode system (2, 3, and 4), a reagent, and an insulating layer (5). The insulating layer (5) covers a part of the electrode system (2, 3, and 4). Also, a closed region (6) without the insulation layer is formed at where the reagent is. The closed region (6) is provided with an enclosing border having no sharp corner. The reagent covers the closed region (6) and does not go beyond the enclosing border. The biosensor also comprises an assisted diffusion electrode (12). The use of the enclosing border having no sharp corner and of the assisted diffusion electrode (12) reduces the edge effect of the reagent, allows the reagent to diffuse uniformly at response areas of the electrodes, effectively controls the amount of reagent used, reduces product costs, and allows for simple manufacturing.