Multi-Size Colloidal Structure for Tunable Reflective Crystal Films

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing colloidal crystal films experience a significant decrease in light reflectivity when the concentration of colloidal particles is outside a predetermined range, making it difficult to adjust the reflection peak wavelength effectively.

Innovation Solution

A colloidal structure comprising multiple types of colloidal particles with varying average sizes and a matrix that fixes these particles, allowing for a regular array with a coefficient of variation less than 20%, enabling adjustment of the reflection peak wavelength while maintaining high light reflectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the concentration of colloidal particles is changed to adjust the reflection peak wavelength, then the reflection peak wavelength is可调, but the light reflectivity decreases significantly when the concentration goes out of a predetermined range

Engineering Contradiction:
Improveadjustability of reflection peak wavelengthVSAvoidlight reflectivity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent divides the colloidal particles into multiple size groups (first colloidal particles with larger size and second colloidal particles with smaller size). By segmenting the particle population into distinct size categories rather than using a single concentration parameter, the system can independently adjust the reflection peak wavelength through size ratios while maintaining high reflectivity through controlled particle distribution in each size segment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by specifying different size characteristics for different particle populations within the same colloidal crystal. The first colloidal particles and second colloidal particles have deliberately different average sizes with controlled coefficients of variation, creating local size variations that enable wavelength tuning without sacrificing overall reflectivity. This local differentiation in particle size quality allows the system to achieve both adaptability and reliability.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If the concentration of colloidal particles is changed to adjust the reflection peak wavelength, then the reflection peak wavelength is可调, but the method becomes complex

Engineering Contradiction:
Improveadjustability of reflection peak wavelengthVSAvoidcomplexity of production method
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent uses parameter changes by systematically varying the average particle size and size distribution parameters of colloidal particles. By changing the average size of first and second colloidal particles and their respective coefficients of variation, the reflection peak wavelength can be adjusted through well-defined parameter modifications rather than complex procedural changes. This approach simplifies the production method while maintaining adjustability.

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 colloidal structure can efficiently adjust the reflection peak wavelength by adjusting the content ratio and particle sizes of the colloidal particles, maintaining high light reflectivity and allowing for a simple method to shift the peak to arbitrary positions.

Implementation Method 1

When light enters this colloidal crystal, diffraction interference of the light occurs inside the colloidal crystal, and accordingly, a phenomenon that the collooidal crystal reflects light with a specific wavelength occurs due to a periodic structure thereof

Methodology Applied
Scientific EffectDiffraction interference: Diffraction

Implementation Method 2

An assembly in which nano-sized colloidal particles are arrayed three-dimensionally and periodically is called a colloidal crystal

Methodology Applied
Scientific EffectSelf-assembly: Self-Assembly

Implementation Method 3

a polymerization step of fixing the plurality of types of the colloidal particles by a polymer by polymerizing the monomer in the coating film

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentEP3812428B1Colloidal structure, multi-colloidal structure, and production method for colloidal structure
Publication Date: 2025.12.03 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3812428B1 patent drawingFigure 1~2
  • EP3812428B1 patent drawingFigure 3
  • EP3812428B1 patent drawingFigure 4(a)~4(c)

AI summary

A colloidal structure (10) includes a plurality of types of colloidal particles, and a matrix (3) that fixes the colloidal particles. The plurality of types of the colloidal particles include at least first colloidal particles (1) and second colloidal particles (2), which are different in average particle size from each other. Then, the plurality of types of the colloidal particles form a regular array in a matrix. A multi-colloidal structure (20) includes a plurality of the colloidal structures. A method for producing a colloidal structure includes: a dispersion liquid preparation step of preparing a colloidal dispersion liquid by dispersing a plurality of types of colloidal particles together with a monomer; a coating film generation step of coating the colloidal dispersion liquid on a substrate, and generating a coating film; and a polymerization step of polymerizing the monomer in the coating film.