Patterned Electrochromic Electrodes Without ITO

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Indium tin oxide (ITO) based transparent conductive coatings are costly, brittle, and complex to manufacture, making them unsuitable for flexible electrochromic devices, which require high conductivity, flexibility, and transparency.

Innovation Solution

A method involving a patterned arrangement of electrically conductive materials, such as silver nanoparticles or carbon nanotubes, in contact with electrochromic materials, allowing for the use of non-ITO materials and reducing fabrication costs through techniques like inkjet printing and self-assembly, enabling the creation of transparent electrodes with high transparency and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ITO is used as transparent conductive coating, then conductivity and transparency are achieved, but cost increases and flexibility is lost due to brittleness

Engineering Contradiction:

ImproveconductivityVSAvoidcost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive ITO with inexpensive alternatives such as silver nanoparticle inks, carbon nanotube inks, and conductive polymer inks that can be deposited via low-cost printing techniques. These alternative materials achieve comparable conductivity while dramatically reducing material and manufacturing costs, making transparent electrodes economically viable for large-area applications

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent employs flexible substrate materials such as polyethylene terephthalate (PET), polyimide, and other plastic films instead of rigid glass substrates. The thin-film deposition techniques enable creation of flexible transparent electrodes that can withstand bending and deformation, enabling wearable and flexible electrochromic devices

Inventive Principle:

Principle #30Flexible shells and thin films

2Reliability

If ITO is used as transparent conductive coating, then conductivity is achieved, but manufacturing complexity increases due to etching processes

Engineering Contradiction:

ImproveconductivityVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical etching processes with direct printing methods. Conductive ink formulations containing silver nanoparticles, carbon nanotubes, or conductive polymers are deposited directly onto substrates in desired patterns using inkjet printing, screen printing, or other low-cost printing techniques, eliminating the need for photolithography and chemical etching steps

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The conductive ink formulations are designed to self-assemble or self-organize into functional patterns upon deposition. The materials inherently form continuous conductive networks through particle aggregation, sintering, or polymerization processes that occur automatically during or after deposition, reducing the need for additional processing steps

Inventive Principle:

Principle #25Self-service

3Illumination intensity

If patterned arrangement of conductive material is used, then transparency is improved, but manufacturing precision requirements increase

Engineering Contradiction:

ImprovetransparencyVSAvoidpatterning precision

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent creates patterned transparent electrodes where conductive material is distributed non-uniformly across the substrate. By controlling the local concentration and distribution of conductive particles or polymers in specific regions, the patent achieves both transparency in open areas and sufficient conductivity in conductive pathways, optimizing both optical and electrical properties locally

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs patterned arrangements where conductive material covers only portions of the substrate rather than forming continuous full-coverage layers. This partial coverage approach maintains high transparency in non-conductive regions while providing sufficient conductivity in patterned regions, achieving the desired balance without requiring complete surface coverage

Inventive Principle:

Principle #16Partial or excessive action

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

This approach results in electrochromic devices with high transparency, low sheet resistance, and stability to multiple bending cycles, achieving a contrast of 72% at 633 nm, while avoiding the limitations of ITO, such as brittleness and high cost.

Implementation Method 1

electrochromic materials, as well as materials suitable for use as transparent conductive coatings

Methodology Applied

Scientific EffectElectrochromism: Electrochromism

Data Source

PatentUS10895794B2Electrochromic device having a patterned electrode free of indium tin oxide (ITO)

Publication Date: 2021.01.19 YISSUM RESEARCH DEVELOPMENT COMPANY OF THE HEBREW UNIVERSITY OF JERUSALEM LTD

AI summary

A method of manufacturing an electrochromic device is provided. The method includes providing a patterned arrangement of an electrically conductive material; and applying one or more layers of an electrochromic material to the patterned arrangement, wherein at least a portion of the electrochromic material is in electrical contact with the electrically conductive material. An electrochromic device and an electrochromic ink composition are also provided.