Electrochromic Interference Layer for Reversible Full-Color Switching

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Solution Overview

Problem

Existing electronic display devices consume unnecessary energy to maintain color or pattern displays, and prior art fails to achieve full-color regulation with a wide color gamut and efficient energy use.

Innovation Solution

A full-color reversible switching device utilizing electrochemistry with a color-changing layer, electrolyte, and counter electrode, where electrochemical reactions adjust the active material layer's thickness to achieve full-color changes through voltage control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional electrochromic devices using viologen compounds are used, then blue coloration is achieved, but reversible switching to other colors (especially red) is not possible

Engineering Contradiction:
Improvecolor switching capabilityVSAvoidreversibility of color change
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The device is segmented into multiple independently controllable electrochromic layers, each capable of displaying different colors. This allows selective activation of individual layers to achieve various color combinations, enabling reversible switching between multiple colors including red, blue, green, and yellow.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses composite electrochromic materials comprising viologen compounds combined with other electrochromic dyes or pigments in separate layers. This composite structure enables each layer to contribute different color properties, allowing versatile and reversible color switching when layers are selectively activated or deactivated.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If multiple electrochromic layers with different colors are stacked, then full-color display is achieved, but device structure becomes complex

Engineering Contradiction:
Improvecolor display rangeVSAvoidlayer structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Each electrochromic layer is designed with universal switching capability through independent electrode control. All layers can be switched on or off independently, allowing any combination of colors to be displayed. This multi-functional design enables a single device structure to achieve full-color display without requiring complex mechanical switching mechanisms.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The device employs dynamic electrical control to switch between different color states. By applying different voltage patterns to each layer, the device can dynamically transition between various color combinations, providing flexible and reversible color changing capability without physical reconfiguration.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If viologen compounds are used for electrochromic switching, then blue coloration is achieved, but red coloration cannot be obtained

Engineering Contradiction:
Improvecolor rangeVSAvoiddiversity of electrochromic materials
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The invention combines viologen compounds (providing blue coloration) with other electrochromic materials such as methylene blue, eosin, or various pigments in separate layers. This composite material approach allows each material to contribute its characteristic color, achieving a broad color range including red, blue, green, and yellow through selective layer activation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different electrochromic materials are segmented into separate controllable layers. This allows the use of diverse materials without mixing them, where each layer can be independently switched to contribute its specific color property to the overall display, expanding the achievable color range.

Inventive Principle:
Principle #1Segmentation

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 device achieves rich tunable colors across the entire color gamut with reversible switching at low voltage, no additional energy needed for color maintenance, and has high brightness and saturation, suitable for energy-saving displays, decoration, anti-counterfeiting, and energy-saving building materials.

Implementation Method 1

an electrochromic layer including a viologen compound and a cyclic voltammetry curve of the electrochromic layer shows that the electrochromic layer has a first reduction peak and a first oxidation peak

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Implementation Method 2

the electrochromic layer has a first reduction peak and a first oxidation peak in a cyclic voltammetry curve

Methodology Applied
Scientific EffectElectrochemical reduction: Reduction

Implementation Method 3

the electrochromic layer has a first reduction peak and a first oxidation peak in a cyclic voltammetry curve

Methodology Applied
Scientific EffectElectrochemical oxidation: Oxidation

Implementation Method 4

a transparent conductive oxide layer

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4439168B1Electrically-controlled color-changing device achieving reversible switching of all colors, manufacturing method therefor and use thereof
Publication Date: 2025.08.27 SUZHOU INST OF NANO TECH & NANO BIONICS CHINESE ACEDEMY OF SCI
  • EP4439168B1 patent drawingFigure 1
  • EP4439168B1 patent drawingFigure 2
  • EP4439168B1 patent drawingFigure 3~4

AI summary

The present application discloses a full-color reversible switching device controlled by electrochemistry, and its preparation method and use. The device controlled by electrochemistry includes a color-changing layer, an electrolyte and a counter electrode. The color-changing layer includes a substrate, a conductive layer and an active material layer. The active material layer and the conductive layer form a physical interference color. The electrolyte is connected to the conductive layer or the active material layer. When an electrochemical reaction occurs between the electrolyte and a surface of the conductive layer or the active material layer, the thickness of the active material layer changes. The device controlled by electrochemistry provided by the present application has rich tunable colors that can cover the entire color gamut, and can achieve reversible switching of colors at a small voltage; and moreover, the device controlled by electrochemistry provided by the present application has memory characteristics of the regulated colors, does not require additional energy input to maintain the colors, is energy-saving and environmentally friendly, and has the characteristics of high brightness and high saturation, thereby having broad application prospects in energy-saving display, decoration, anti-counterfeiting, batteries and the like fields.