Chiral Domain Patterning in Mesogenic Thin Films by Laser Heating

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Solution Overview

Problem

Existing methods for controlling the chirality of morphologically chiral liquid crystal phases require the use of enantiomerically pure compounds or circularly polarized light, leading to increased costs and complexity, and lack efficient methods for controlling the spatial arrangement of chiral domains in thin films.

Innovation Solution

A method involving laser illumination to control the spatial arrangement of chiral domains by heating mesogenic compounds above their isotropisation temperature, using a digital micromirror device to shape the illumination, and controlling the crystallisation front to achieve desired chirality patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If circularly polarized light is used to induce chirality, then the chirality of liquid crystal phases can be controlled, but the system complexity and cost increase

Engineering Contradiction:
Improvechirality control precisionVSAvoidsystem complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the need for circularly polarized light and chiral compounds from the system. Instead of using external chiral factors, the invention utilizes the inherent conformational chirality of achiral mesogenic compounds during their phase transition, thereby simplifying the system while maintaining chirality control capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention enables the achiral mesogenic compound to self-generate chirality through conformational changes during crystallization. The compound serves itself by adopting chiral conformations spontaneously during phase transition, eliminating the need for external chiral inducers or complex optical equipment

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If chiral additives are used to control morphology, then the chirality of liquid crystal phases can be controlled, but the system complexity and cost increase

Engineering Contradiction:
Improvechirality control precisionVSAvoidmanufacturing simplicity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent removes chiral additives from the system and instead utilizes achiral mesogenic compounds that inherently exhibit conformational chirality during phase transition. This extraction of chiral additives simplifies the manufacturing process while maintaining the ability to control chiral domain formation

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention controls chirality by changing physical parameters (temperature, cooling rate) during phase transition rather than by adding chiral compounds. By adjusting crystallization conditions, the handedness and spatial arrangement of chiral domains can be controlled without introducing additional chemical complexity

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If enantiomerically pure compounds are used, then the chirality can be controlled, but the cost increases

Engineering Contradiction:
Improvechirality control precisionVSAvoidmaterial cost
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent extracts and eliminates the requirement for enantiomerically pure compounds. Instead, it uses readily available achiral mesogenic compounds that spontaneously form chiral conformations during crystallization, significantly reducing material costs while maintaining chirality control

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention inverts the conventional approach by starting with achiral compounds rather than chiral ones. By controlling the phase transition of achiral mesogenic compounds, chiral domains with specific handedness are formed, reversing the traditional methodology and reducing material costs

Inventive Principle:
Principle #13The other way round (Inversion)

4Manufacturing precision

If the crystallisation front is controlled to achieve desired patterns, then the spatial arrangement of chiral domains can be controlled, but the process complexity increases

Engineering Contradiction:
Improvespatial arrangement precisionVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by controlling the crystallization front propagation during phase transition. By managing the temperature gradient and cooling process, the spatial arrangement of chiral domains is predetermined and controlled, achieving desired patterns through process control rather than complex post-processing

Inventive Principle:
Principle #10Preliminary 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

Enables the creation of arbitrarily designed patterns of chiral domains with opposite handedness, simplifying the process and reducing costs by using only achiral compounds, and allowing easy verification through polarisers.

Implementation Method 1

heating is carried out by means of area illumination with laser light of a wavelength corresponding to the high absorbance of the melted mesogenic compound

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

area illumination with laser light of a wavelength corresponding to the high absorbance of the melted mesogenic compound

Methodology Applied
Scientific EffectAbsorption of electromagnetic radiation: Absorption (EM radiation)

Implementation Method 3

the area of a thin organic film of a mesogenic compound forming a conglomerate of domains is heated above the isotropisation temperature of the mesogenic compound

Methodology Applied
Scientific EffectPhase transition: Phase Change

Implementation Method 4

controlling the crystallisation front to achieve desired chirality patterns

Methodology Applied
Scientific EffectCrystallisation: Crystallisation

Implementation Method 5

allowing easy verification through polarisers

Methodology Applied
Scientific EffectOptical activity: Polarisation

Data Source

PatentEP4513241B1Method of controling domain of organic compounds showing conformational chirality
Publication Date: 2025.12.10 UNIWERSYTET WARSZAWSKI
  • EP4513241B1 patent drawingFigure 2~1C3
  • EP4513241B1 patent drawingFigure 3~4

AI summary

The subject of the present invention is a method for controlling the spatial arrangement of domains of mesogenic compounds, exhibiting the ability to synchronise chirality by controlled synchronisation of conformational chirality, characterised in that an area of a thin film of a compound forming a conglomerate of domains is heated above the isotropisation temperature of a given compound until a specific chirality is obtained in a given area, and the shape of the heated area corresponds to a selected pattern enabling the control of the crystallisation front, wherein the heating is carried out by means of area illumination with laser light of a wavelength corresponding to the high absorbance of the melted compound and/or area heating of a substrate on which the thin film of the compound is placed and/or by area illumination with laser light of a wavelength corresponding to the high absorbance of a dye added to the film.