Electrochemical Sensor Porous Junction Plug Aperture Design

Solution Overview

Problem

Existing electrochemical sensors face challenges in maintaining a stable reference electrode potential due to contamination or dilution of the reference electrolyte, especially in harsh environments, and require an effective liquid junction with a high resistance factor that is both cost-effective and durable.

Innovation Solution

An electrochemical sensor design featuring a housing with a porous junction plug and a cross member impermeable to the target fluid, where the cross member defines a specific aperture for electrochemical communication between the target fluid and the reference electrolyte, enhancing the ionic exchange path and resistance factor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex structural configuration with multiple layers is used to establish a tortuous path for ions, then the resistance factor is improved, but the manufacturing cost and time increase

Engineering Contradiction:

Improveresistance factorVSAvoidmanufacturing cost and time

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The liquid junction is divided into two functional segments: a junction plug made of porous material that provides the tortuous path, and a cross member that provides structural support and defines the aperture. This segmentation allows each component to be optimized independently for its specific function while simplifying the overall manufacturing process.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The junction plug is made of porous material that creates a tortuous path for ions through its pore structure. This porous structure inherently provides high resistance factor without requiring complex multi-layer assemblies, as the tortuous path is built into the material itself rather than constructed from multiple components.

Inventive Principle:

Principle #31Porous materials

2Reliability

If multiple layers are assembled together to create a tortuous path, then the resistance factor is improved, but the device complexity increases

Engineering Contradiction:

Improveresistance factorVSAvoidstructural complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The liquid junction is divided into two functional segments: a junction plug made of porous material that provides the tortuous path, and a cross member that provides structural support and defines the aperture. This segmentation allows each component to be optimized independently for its specific function while simplifying the overall manufacturing process.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The liquid junction combines two different materials with complementary properties: porous material for creating the tortuous ion path and impermeable material for structural support and aperture definition. This composite approach achieves high resistance factor with simpler overall structure compared to multiple layers of the same material.

Inventive Principle:

Principle #40Composite materials

3Reliability

If the liquid junction allows ionic communication between reference electrolyte and target fluid, then the reference electrode potential stability is improved, but the risk of contamination and dilution increases

Engineering Contradiction:

Improvereference electrode potential stabilityVSAvoidcontamination and dilution risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The junction plug is made of porous material that creates a tortuous path for ions through its pore structure. This porous structure inherently provides high resistance factor without requiring complex multi-layer assemblies, as the tortuous path is built into the material itself rather than constructed from multiple components.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The junction plug acts as an intermediary between the reference electrolyte and the target fluid, allowing controlled ionic communication while physically separating the two fluids. The porous structure of this intermediary provides the necessary ion exchange pathway while maintaining the barrier function to prevent direct mixing and contamination.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 design improves the stability and resistance of the reference electrode by ensuring ionic exchange occurs through a controlled aperture, reducing contamination risks and maintaining sensor performance over time, even in harsh environments, while being more cost-effective and efficient to manufacture.

Implementation Method 1

a junction plug comprising a porous material... enabling ionic exchange must pass through the aperture

Methodology Applied

Scientific EffectPorosity: Porosity

Implementation Method 2

a cross member impermeable to a target fluid positioned between the junction plug and the cavity... defines an aperture to enable electrochemical communication

Methodology Applied

Scientific EffectPermeation: Permeation

Data Source

PatentUS7867371B2Electrochemical sensor and method of manufacture

Publication Date: 2011.01.11 GEORG FISCHER SIGNET LLC

AI summary

An electrochemical sensor is provided that includes a housing defining a cavity for a reference electrolyte and defining an opening to the cavity configured to be proximate to a target fluid. The sensor further includes a junction plug comprising a porous material and a cross member impermeable to a target fluid positioned between the junction plug and the cavity. The cross member includes a planar portion disposed against the junction plug that defines an aperture to enable electrochemical communication between the target fluid and the reference electrolyte.