Solid-State Reference Electrode With Ion Exchange Against Interference

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Solution Overview

Problem

Traditional liquid-filled reference electrodes suffer from leakage, contamination, and interference from ionic species in the analyte, leading to unstable reference potentials and difficulty in miniaturization.

Innovation Solution

A solid state reference electrode with a polymeric composite loaded with inorganic salt and a solid ion-exchange material that immobilizes interfering ions, maintaining a stable reference potential by exchanging them with non-interfering ions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a liquid-filled reference electrode is used, then a stable reference potential can be provided, but the electrode is prone to electrolyte leakage and contamination

Engineering Contradiction:
Improvereference potential stabilityVSAvoidelectrolyte leakage and contamination
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the physical state of the electrolyte from liquid to solid, eliminating the liquid junction and its associated leakage problems. The solid electrolyte is contained within a porous barrier that allows ionic communication while preventing liquid leakage and contamination of the analyte.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite structure combining a solid electrolyte material with a porous barrier layer. This composite design maintains the stability benefits of liquid-filled electrodes while adding the leakage prevention capabilities of solid-state construction.

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If a liquid junction is used to provide ionic communication, then electrochemical cell completion is achieved, but junction potential errors and contamination occur

Engineering Contradiction:
Improveionic communicationVSAvoidjunction potential accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent transitions from a liquid junction to a solid-state ion-exchange membrane junction. This maintains ionic communication necessary for electrochemical cell completion while eliminating the liquid junction potential errors and contamination issues inherent in liquid-filled designs.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a solid ion-exchange membrane as an intermediary between the reference electrolyte and the analyte. This membrane facilitates ionic communication while blocking liquid mixing, thereby maintaining measurement precision by eliminating junction potential errors.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If traditional reference electrode construction is used, then reference potential stability is maintained, but miniaturization is difficult

Engineering Contradiction:
Improvereference potential stabilityVSAvoidelectrode size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent changes the electrolyte from liquid to solid state, which fundamentally enables miniaturization. The solid electrolyte requires minimal volume to maintain stable reference potential, allowing the entire electrode assembly to be reduced to a compact size suitable for microelectrode applications.

Inventive Principle:
Principle #35Parameter changes

4Volume of moving object

If polymeric composite is used to embed reference element, then miniaturization is enabled, but the composite degrades in harsh analyte conditions

Engineering Contradiction:
Improveelectrode sizeVSAvoidcomposite durability
Core Design Contradiction:
Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The patent employs a composite material system consisting of a chemically resistant polymer matrix combined with a solid electrolyte and ion-exchange membrane. This multi-component composite maintains miniaturization benefits while providing enhanced durability against degradation from harsh analyte conditions through the synergistic properties of its constituent materials.

Inventive Principle:
Principle #40Composite materials

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 electrode provides a stable and reproducible reference potential, resistant to interference from ionic species, allowing for miniaturization and improved durability in harsh environments.

Implementation Method 1

the solid ion-exchange material immobilises interfering ions present in the analyte by exchange with non-interfering ions present in the material

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Implementation Method 2

a water-permeable polymeric matrix loaded with a solid inorganic salt comprising a reference anion

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP4055378B1Interference resistant solid state reference electrode
Publication Date: 2026.03.25 COMMONWEALTH SCI & IND RES ORG
  • EP4055378B1 patent drawingFigure 1~2
  • EP4055378B1 patent drawingFigure 3~4
  • EP4055378B1 patent drawingFigure 5~6

AI summary

The invention provides a solid state reference electrode comprising: a reference element in ionic communication with a composite, the composite comprising a water-permeable polymeric matrix loaded with a solid inorganic salt comprising a reference anion; an electrode surface for contacting an analyte; and a solid ion-exchange material located between the electrode surface and the reference element, the solid ion-exchange material comprising one or more non-interfering ions, wherein in use the solid ion-exchange material immobilises one or more interfering ions, when present in solution in the analyte, by exchange with the non-interfering ions.