Electrochromic Color-Layer Coupling for Angle-Dependent Camouflage

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Solution Overview

Problem

Existing electrochromic devices fail to effectively couple pigmentary and structural colors for dynamic color tunability and angle-dependent light variations, limiting their applications in camouflage, displays, and protective coatings.

Innovation Solution

An electrochromic device comprising a pigmentary color layer and a structural color layer, where the structural color layer is placed adjacently along the optical path, allowing for angle-dependent light variations and reversible color switching by electric voltage, utilizing electrochromic materials like ECPs and metastable colloidal crystals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If only pigmentary color materials are used in electrochromic devices, then the device can achieve color switching through light absorption, but the device lacks angle-dependent light variations and broad color gamut

Engineering Contradiction:
Improvecolor gamut and angle-dependent visibilityVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines pigmentary color materials (for absorption-based color switching) and structural color materials (for angle-dependent light variations) into a single electrochromic device. The pigmentary layer and structural color layer are integrated along the optical path, allowing the device to simultaneously achieve broad color gamut, dynamic color expression, and angle-dependent visibility control that neither layer could achieve alone.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The device employs a composite structure comprising both pigmentary color materials and structural color materials. The pigmentary color layer contains electrochromic materials that change absorption properties under voltage, while the structural color layer contains materials with periodic structures that produce angle-dependent optical effects. This composite material approach enables the device to overcome the limitations of single-material systems.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If only structural color materials are used in electrochromic devices, then the device can achieve angle-dependent light variations, but the device lacks dynamic color switching capability and broad color gamut

Engineering Contradiction:
Improvedynamic color switching and color gamutVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent integrates structural color materials (providing angle-dependent light variations) with pigmentary color materials (providing dynamic color switching) into a unified electrochromic device. The combination allows the device to achieve both angle-dependent visibility and dynamic color gamut expansion that neither material type could provide independently.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The device uses a composite structure where structural color materials with periodic structures are combined with electrochromic pigmentary materials. The structural color layer provides angle-dependent optical effects while the pigmentary layer provides voltage-controlled color switching, creating a synergistic system that overcomes the limitations of using structural color materials alone.

Inventive Principle:
Principle #40Composite materials

3Illumination intensity

If the structural color layer has high transmittance and thin thickness, then the device can achieve noticeable angle-dependent light variations, but the structural color layer may not provide sufficient color intensity

Engineering Contradiction:
Improveangle-dependent light variation visibilityVSAvoidcolor intensity
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent combines the structural color layer (optimized for angle-dependent light variations with appropriate transmittance and thickness) with the pigmentary color layer (optimized for color intensity). The pigmentary layer compensates for any color intensity loss in the structural color layer, while the structural color layer provides the angle-dependent optical effects, achieving both visibility and intensity requirements.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4078280B1An electrochromic device based on two color layers and methods of fabricating same
Publication Date: 2026.02.11 AMBILIGHT INC
  • EP4078280B1 patent drawingFigure 1A~1B
  • EP4078280B1 patent drawingFigure 2~3
  • EP4078280B1 patent drawingFigure 4

AI summary

An electrochromic device with one pigmentary color layer and one structural color layer is disclosed. The pigmentary color layer comprises electrochromic materials, which allow reversible and gradient switches between a colored state and a bleached state by electric field. In a colored state, the electrochromic device presents saturated pigmentary-structural additive color. In a bleached state, the structural color gradually vanished and leads to the optical transmissive state. The color coupling between these two color layers provides the disclosed devices with broader color gamut and angle-dependent optical response. Multiplexed and patterned devices have been further fabricated to demonstrate bio-mimic camouflage potentials.