Ion-Selective Membrane Barrier for Stable Porous Sensor Storage

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Solution Overview

Problem

Analytical devices using porous substrates face a loss of measurement sensitivity due to plasticizer seepage and diffusion into the substrate during long-term storage, especially under high temperatures, affecting ion concentration responsiveness.

Innovation Solution

Incorporating a protective layer in the porous substrate near the ion selective membrane to inhibit plasticizer penetration, using materials like polyimide or fluorine resin to seal the interface between the membrane and substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a porous substrate is used for the analytical device, then ease of manufacture and low cost are improved, but measurement sensitivity deteriorates during long-term storage due to plasticizer seepage

Engineering Contradiction:
Improveease of manufactureVSAvoidmeasurement sensitivity
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

A protective layer is introduced as an intermediary between the porous substrate and the ion-selective membrane. This protective layer prevents direct contact between the plasticizer in the membrane and the porous substrate, thereby blocking the capillary-driven seepage of plasticizer while maintaining the overall structure and function of the analytical device.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The protective layer is applied in advance to prevent the harmful capillary action from occurring. By creating this barrier before storage, the device is pre-protected against plasticizer loss that would otherwise occur during long-term storage, eliminating the need for special storage conditions.

Inventive Principle:
Principle #9Preliminary anti-action

2Reliability

If the ion selective membrane contains liquid plasticizer for ion transport, then measurement function is improved, but plasticizer seepage into the porous substrate occurs during storage

Engineering Contradiction:
Improvemeasurement functionVSAvoidplasticizer loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The protective layer serves as a mediator that separates the liquid plasticizer-containing membrane from the porous substrate. It allows the membrane to retain its liquid plasticizer for proper ion transport function while preventing the plasticizer from migrating into the porous substrate through capillary action.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If high temperature storage conditions are applied, then device portability and storage flexibility are improved, but plasticizer diffusion is accelerated and measurement sensitivity is reduced

Engineering Contradiction:
Improvestorage flexibilityVSAvoidmeasurement sensitivity
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The protective layer is applied in advance to counteract the accelerated plasticizer diffusion that occurs at high temperatures. By blocking the capillary pathways before temperature-induced diffusion begins, the device can be stored in flexible conditions including high temperatures without losing measurement sensitivity.

Inventive Principle:
Principle #9Preliminary anti-action

4Volume of moving object

If the porous substrate structure is used, then device miniaturization is improved, but capillary phenomenon accelerates plasticizer seepage

Engineering Contradiction:
Improvedevice sizeVSAvoidplasticizer seepage
Core Design Contradiction:
Volume of moving objectVSLoss of substance

Solution Approach 1:

The protective layer acts as an intermediary that eliminates the harmful capillary phenomenon in miniaturized devices. By coating the porous substrate or forming a non-porous barrier layer, it prevents the capillary-driven plasticizer seepage that would otherwise be accelerated in the small-scale geometry of miniaturized analytical devices.

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

Maintains measurement sensitivity and stability of potential readings for selected ions over extended periods, even without low-temperature storage requirements.

Implementation Method 1

the seeping of the plasticizer is accelerated by the capillary phenomenon of the porous substrate

Methodology Applied
Scientific EffectCapillary phenomenon: Capillary Action

Data Source

PatentEP4711753A1Analysis device
Publication Date: 2026.03.18 CANON KK
  • EP4711753A1 patent drawingFigure 1A~1B
  • EP4711753A1 patent drawingFigure 2A~2B
  • EP4711753A1 patent drawingFigure 3

AI summary

A purpose is to provide an analytical device capable of maintaining good measurement sensitivity even after long-term storage and obtaining a proper potential for selected ions. Provided is an analytical device comprising: a porous substrate; an electrode formed in an inside of, on a surface of, or from the inside to the surface of the porous substrate; an ion selective membrane covering the electrode; and a protective layer, wherein the ion selective membrane comprises a plasticizer; and the protective layer is formed in the inside of the porous substrate as close to at least a portion of the ion selective membrane and comprises a component inhibiting penetration of the plasticizer.