Ferroelectric Polymer Electrode Interface for Deformation Reliability

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Solution Overview

Problem

Ferroelectric polymer-based electromechanical devices suffer from electrode deterioration due to reactions between metal electrodes and the active layer, leading to connection breaks and reduced reliability, especially under deformation.

Innovation Solution

Incorporating poly(3,4-ethylenedioxythiophene) interface layers between the ferroelectric polymer active layer and metal electrodes to prevent direct contact and reactions, enhancing the interface quality and flexibility to absorb deformation stresses, while using silver particles and carbon layers for conductivity and mechanical support.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal electrodes are used in direct contact with the ferroelectric polymer active layer, then electrical conductivity is ensured, but electrode deterioration occurs due to chemical reactions leading to connection breaks and reduced reliability

Engineering Contradiction:

Improvedevice reliabilityVSAvoidelectrode deterioration

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

An interface layer comprising poly(3,4-ethylenedioxythiophene) is introduced between the metal electrode and the ferroelectric polymer active layer. This intermediary layer prevents direct contact and chemical reactions between the metal electrode and active layer, thereby eliminating electrode deterioration while maintaining electrical conductivity through the interface layer.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the electromechanical device is subjected to significant deformations to enable flexible printed circuit applications, then adaptability is improved, but connection breaks occur in the electrodes leading to malfunction

Engineering Contradiction:

ImproveflexibilityVSAvoidconnection reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The electrode structure is designed as a composite comprising a metal layer for electrical conductivity and a poly(3,4-ethylenedioxythiophene) interface layer for mechanical flexibility and chemical stability. This composite structure allows the electrode to withstand significant deformations without connection breaks, enabling flexible printed circuit applications while maintaining reliable electrical connections.

Inventive Principle:

Principle #40Composite materials

3Reliability

If interface layers are added between the electrode and active layer to prevent reactions, then reliability is improved, but device complexity increases

Engineering Contradiction:

Improveconnection stabilityVSAvoidlayer structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The interface layer is implemented as a thin film of poly(3,4-ethylenedioxythiophene) that provides both chemical protection and mechanical flexibility. This thin film approach prevents chemical reactions between the metal electrode and active layer while minimizing the increase in device complexity, as the layer is deposited in a single step and maintains the overall thin-film structure of the electromechanical device.

Inventive Principle:

Principle #30Flexible shells and thin films

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 solution significantly improves the reliability of electromechanical devices by reducing electrode degradation and maintaining performance under mechanical stress, ensuring robust connections and efficient polarization.

Implementation Method 1

the first and the second interface layer being interposed between the active layer and respectively the first and the second metal layer

Methodology Applied

Scientific EffectChemical barrier effect:

Implementation Method 2

an active layer comprising a ferroelectric polymer, such as a poly(vinylidene fluoride) or a poly(vinylidene-co-trifluoroethylene fluoride) copolymer

Methodology Applied

Scientific EffectFerroelectric effect:

Implementation Method 3

at least one of the first and of the second electrode includes at least one of the metal particles and metal wires

Methodology Applied

Scientific EffectMechanical deformation absorption: Elasticity

Data Source

PatentUS11903322B2Electromechanical device based on ferroelectric polymers and methods of manufacturing such a device

Publication Date: 2024.02.13 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES

AI summary

An electromechanical device comprising: first and second electrodes each comprising a metal layer; an active layer comprising at least one ferroelectric polymer and disposed between the first and the second electrode. The first electrode and the second electrode each comprise an interface layer comprising poly(3,4-ethylenedioxythiophene). Each interface layer is interposed between the active layer and the corresponding metal layer. The invention further relates to a method for manufacturing such a device.