Bioelectrode and method for manufacturing same

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Solution Overview

Problem

Existing bioelectrodes face challenges such as poor breathability leading to overheating and rash formation, inadequate flexibility and moisture resistance, and issues with conductivity stability after washing.

Innovation Solution

A bioelectrode with a multilayer structure of a conductor and a non-conductive fiber base material, where the conductor contains carbon black and a polyurethane resin, with specific ratios and dispersion characteristics to ensure flexibility, durability, and consistent conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If gel electrodes or rubber electrodes are used, then flexibility and adhesion to body surface are improved, but breathability deteriorates causing overheating and rash

Engineering Contradiction:
Improveflexibility and adhesionVSAvoidbreathability
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The electrode is divided into multiple layers including a breathable mesh substrate, conductive polymer coating layer, and elastic adhesive layer. This segmentation allows each layer to perform its specific function: the mesh provides breathability, the conductive polymer provides conductivity, and the adhesive layer provides attachment, thereby resolving the contradiction between flexibility/adhesion and breathability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrode uses a composite structure combining mesh fabric, conductive polymer (PEDOT:PSS), and elastic adhesive materials. This composite approach integrates the advantages of each material: the mesh provides breathability and flexibility, the conductive polymer provides electrical conductivity and comfort, and the adhesive layer provides secure attachment, thus achieving both good adhesion and breathability simultaneously.

Inventive Principle:
Principle #40Composite materials

2Reliability

If thin metal plate electrodes are used, then conductivity is improved, but flexibility and suitability for body surface contact deteriorate

Engineering Contradiction:
ImproveconductivityVSAvoidflexibility and body surface suitability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces the traditional rigid metal plate structure with a flexible conductive polymer coating on a mesh substrate. This substitution maintains electrical conductivity while providing the flexibility and conformability needed for comfortable body surface contact, eliminating the need for high contact pressure or conductive paste.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The electrode uses a thin film structure where conductive polymer is coated on a flexible mesh substrate. This thin film configuration provides both electrical conductivity and flexibility, allowing the electrode to conform to body surface contours without requiring rigid metal plates or additional conductive paste.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If conductive polymer PEDOT-PSS with olefin binder is used, then conductivity is improved, but washing durability deteriorates due to weak adhesive strength

Engineering Contradiction:
ImproveconductivityVSAvoidwashing durability
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent modifies the adhesive properties of the binder by selecting elastic adhesive materials with appropriate glass transition temperatures and tack characteristics. This parameter adjustment ensures strong adhesion between the conductive polymer layer and the mesh substrate, preventing delamination during washing while maintaining the conductivity provided by the PEDOT:PSS.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The electrode uses a composite adhesive system combining elastic adhesive materials with the conductive polymer layer. This composite structure provides both strong adhesion for washing durability and maintains the electrical conductivity of the PEDOT:PSS, resolving the contradiction between conductivity and washing durability.

Inventive Principle:
Principle #40Composite materials

4Reliability

If carbon black with large amount is used in conductive material, then conductivity is improved, but rubbing fastness deteriorates and color migration occurs

Engineering Contradiction:
ImproveconductivityVSAvoidrubbing fastness and color stability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent optimizes the carbon black content within a specific range (5-20 wt%) rather than using large amounts. This parameter optimization achieves sufficient conductivity while preventing excessive carbon black that would cause poor rubbing fastness and color migration, thus resolving the contradiction between conductivity and color stability.

Inventive Principle:
Principle #35Parameter changes

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 bioelectrode achieves flexibility, high versatility, excellent wet rubbing fastness, and maintains conductivity stability even after repeated washing, making it suitable for comfortable and effective bioelectric signal acquisition.

Implementation Method 1

the conductor contains carbon black and a polyurethane resin

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS20250134436A1Bioelectrode and method for manufacturing same
Publication Date: 2025.05.01 TORAY INDUSTRIES INC

AI summary

A bioelectrode having a textile form, and which is flexible, highly versatile, excellent in fastness, and curbs lowering in conductivity due to washing is described along with a method for manufacturing the same, where the bioelectrode has a multilayer structure of a conductor and a fiber base material composed of non-conductive fibers, in which the conductor contains carbon black and a polyurethane resin, the carbon black being dispersed in a particulate form at least on a surface of the conductor, where a ratio of a longest distance to a shortest distance between particles of the carbon black and adjacent particles of the carbon black (longest distance/shortest distance) is 1 to 20 on the surface of the conductor, and the surface of the conductor has a wet rubbing fastness of grade 4 or higher.