Liquid Crystal Elastomers Filaments for Adaptive Textiles and Soft Robotics: A Processing-Centric Review

Area of Science:

• Materials Science
• Polymer Chemistry
• Soft Matter Physics

Background:

• Liquid crystal elastomers (LCEs) offer significant actuation capabilities for advanced applications.
• Current LCE processing methods are fragmented and non-standardized, hindering industrial scalability.

Purpose of the Study:

• To present an integrated synthesis-to-filament framework for LCEs.
• To address the challenges in translating lab-scale LCE films to continuous filaments.
• To establish scalable processing strategies for LCE filaments.

Main Methods:

• Developed a framework linking molecular formulation, rheological conditioning, and network fixation.
• Utilized benchmark LCE systems (diacrylate mesogens, triazine crosslinkers) with staged Michael-addition.
• Investigated distinct viscosity regimes and their impact on filament properties.
• Examined processing strategies like nozzle design, draw ratios, and in-line UV curing.

Main Results:

• Identified shear-thinning oligomers (30-200 Pa·s) suitable for various spinning techniques.
• Clarified the relationship between viscosity, extrusion parameters, and filament quality.
• Demonstrated how material composition and processing influence alignment retention and actuation performance.
• Established scalable processing windows for defect-free LCE filament formation.

Conclusions:

• The integrated framework enables scalable manufacturing of LCE filaments.
• Standardized processing metrics and sustainable chemistries are crucial for industrial adoption.
• Machine learning can accelerate the development of new LCE formulations for filament production.