Photochromic Host Matrix for Rapid Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing photochromic materials are expensive to manufacture, have slow switching times, and are difficult to replace or repair, limiting their applications and affordability, especially for disposable and large-scale use.

Innovation Solution

A multilayer structure with a homogeneous, flexible photochromic core is created using a roller rolling process that saturates an adhesive layer with a photochrome solution, allowing for rapid switching and easy integration into various forms, including peelable and repositionable formats, reducing production costs and enhancing usability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If photochromic materials are incorporated into solid host matrices (mineral or organic glass), then the material provides stable photochromic function, but the switching time becomes slow due to the rigid structure

Engineering Contradiction:
Improvephotochromic function stabilityVSAvoidswitching time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the physical state parameter of the host matrix from solid (rigid) to liquid (fluid), which fundamentally alters the molecular mobility and relaxation dynamics. This parameter change enables fast switching while maintaining photochromic stability through the liquid crystal or polymer matrix structure.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining photochromic molecules with liquid crystal or polymer matrices. This composite structure provides both the stability needed for reliable photochromic function and the molecular mobility required for fast switching, resolving the contradiction between stability and speed.

Inventive Principle:
Principle #40Composite materials

2Reliability

If traditional manufacturing processes are used to incorporate photochromic substances, then the material achieves photochromic properties, but the manufacturing cost becomes expensive

Engineering Contradiction:
Improvephotochromic propertiesVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the photochromic substance incorporation with the existing liquid crystal or polymer matrix manufacturing process. By combining these functions into a single material system, the patent eliminates separate manufacturing steps and reduces overall production costs while maintaining photochromic properties.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent enables the use of cheaper liquid crystal and polymer materials compared to traditional solid glass matrices, making photochromic products more affordable and suitable for disposable or frequently replaced applications.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If photochromic materials are integrated into fixed structures, then the optical filter function is provided, but the material becomes difficult to replace or repair

Engineering Contradiction:
Improveoptical filter functionVSAvoidreplaceability
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The patent introduces dynamic characteristics by using liquid crystal or polymer matrices that can be applied and removed as flexible coatings or laminates. This dynamic application method allows the photochromic layer to be easily replaced or repaired without damaging the underlying structure, unlike fixed integrated solutions.

Inventive Principle:
Principle #15Dynamics

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 achieves rapid photochromic switching times, reduces manufacturing costs, and allows for adaptable and replaceable photochromic materials, expanding their potential applications and affordability.

Implementation Method 1

Photochromism is the property of a material to react to the intensity of a determined radiation, typically UV radiation, by modifying its properties of absorption of visible light: the material darkens under the effect of the radiation, and brightens in the absence of this radiation. This phenomenon of lightening and darkening is reversible.

Methodology Applied
Scientific EffectPhotochromism: Photochromism

Data Source

PatentEP2300860B1Multilayer structure having a photochromic host matrix and manufacturing method
Publication Date: 2018.09.05 THALES SA
  • EP2300860B1 patent drawingFigure 1~3b
  • EP2300860B1 patent drawingFigure 4a~5b
  • EP2300860B1 patent drawingFigure 6a~7b

AI summary

A photochromic structure MPH comprises a plastic substrate P1 of optical quality, i.e. one with good light transparency, at least one side of which has a layer of adhesive A1 impregnated with a solution of a solvent S with photochromic species CR1, constituting a flexible host matrix M1 for the photochromic species CR1, which is transferred by adhesion onto another substrate. In this way what is obtained is a structure having a flexible photochromic matrix, which is homogeneous and has a rapid switching time, especially a rapid relaxation time. In one configuration, this structure is transferable and advantageously repositionable. It is produced by a method using a roll coating process combined with a system for dispensing the solvated solution of photochromic species upstream of the coating rolls, in which method a strip substrate bearing an adhesive is conveyed by the rolls, and the adhesive is progressively impregnated and then laminated onto another substrate. Application to optical devices.