High-Temperature TPU Conductive Ink for Fatigue-Resistant Heating Traces

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Solution Overview

Problem

Heating elements for electrothermal deicers face issues with material property changes due to etching processes, which affect dimensional tolerances and pose waste disposal challenges, and conductive inks lack sufficient mechanical fatigue resistance.

Innovation Solution

A conductive ink comprising high melting temperature thermoplastic polyurethane and conductive particles, such as silver platelets or nanosilver, with a free radical crosslinker like peroxide, providing enhanced mechanical fatigue resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If chemical etching process is used to create heating elements, then conductive patterns can be formed, but mechanical properties deteriorate and dimensional tolerances are affected

Engineering Contradiction:
Improveconductive pattern formationVSAvoidmechanical properties
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent replaces the chemical etching process with a conductive ink deposition system that uses a carrier fluid to deposit conductive particles and binder material. This substitution eliminates the harmful chemical etching process while maintaining the ability to form conductive heating patterns on the substrate.

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

Solution Approach 2:

The patent employs a composite conductive ink formulation consisting of conductive particles (such as silver, aluminum, or carbon), binder material, and carrier fluid. This composite material system provides both electrical conductivity and mechanical integrity without requiring chemical etching of the substrate.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If chemical etching process is used to create heating elements, then conductive patterns can be formed, but dimensional tolerances are affected

Engineering Contradiction:
Improveconductive pattern formationVSAvoiddimensional tolerances
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces the chemical etching process with a conductive ink deposition system that uses a carrier fluid to deposit conductive particles and binder material. This substitution eliminates the harmful chemical etching process while maintaining the ability to form conductive heating patterns on the substrate.

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

Solution Approach 2:

The patent controls the deposition parameters of the conductive ink, including particle size distribution, binder composition, and carrier fluid properties, to achieve precise control over the conductive pattern dimensions and tolerances without relying on chemical etching processes.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If conventional conductive ink is used, then ease of application is improved, but mechanical fatigue resistance is insufficient

Engineering Contradiction:
Improveease of applicationVSAvoidmechanical fatigue resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent employs a composite conductive ink formulation consisting of conductive particles (such as silver, aluminum, or carbon), binder material, and carrier fluid. This composite material system provides both electrical conductivity and mechanical integrity without requiring chemical etching of the substrate.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the binder material composition and curing parameters to enhance the mechanical fatigue resistance of the conductive ink trace while maintaining ease of application. The binder is formulated to provide flexibility and adhesion that withstands repeated bending cycles.

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 conductive ink exhibits improved fatigue resistance performance in bending cycle tests, making it suitable for applications like rotor blades and fixed wings, and offers robustness against vibration.

Implementation Method 1

The conductive ink may further comprise a free radical crosslinker, such as peroxide

Methodology Applied
Scientific EffectFree radical crosslinking:

Implementation Method 2

The conductive ink may comprise a high melting temperature thermoplastic polyurethane and a plurality of conductive particles

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3836750B1Conductive ink with enhanced mechanical fatigue resistance
Publication Date: 2025.07.16 GOODRICH CORP
  • EP3836750B1 patent drawingFigure 1
  • EP3836750B1 patent drawingFigure 2
  • EP3836750B1 patent drawingFigure 3

AI summary

A conductive ink may comprise a high temperature thermoplastic polyurethane (TPU) and a plurality of conductive particles disposed in the high temperature TPU. The plurality of conductive particles may comprise between 60% and 95% of the conductive ink by weight. The high temperature TPU may include a melting point between 120 °C and 200 °C. The conductive ink may be used for external heated composite structures, such as rotor blades, fixed wings, faring, engine lip electrothermal ice protection, or the like. The conductive ink may have enhanced mechanical fatigue resistance.