3D Printing of Flow-Inspired Anisotropic Patterns with Liquid Crystalline Polymers

Area of Science:

• Materials Science
• Polymer Science
• Additive Manufacturing

Background:

• Biological materials exhibit remarkable anisotropic mechanical properties due to their complex microstructures.
• Synthetically achieving similar directionality in engineered materials is challenging due to manufacturing limitations.

Purpose of the Study:

• To present a 3D printing approach using self-assembling thermotropic liquid crystal polymers (LCPs) to overcome limitations in creating directionally controlled materials.
• To achieve a wide range of mechanical properties by controlling the alignment of nematic domains during printing.

Main Methods:

• Utilized 3D printing of self-assembling thermotropic liquid crystal polymers (LCPs).
• Controlled nematic domain alignment during extrusion to influence material stiffness and strength.
• Investigated the relationship between stiffness, nozzle diameter, and line width to define a design space.
• Demonstrated on-the-fly width changes for printing arbitrary spatially varying directions.

Main Results:

• Achieved a wide range of Young's modulus from 3 to 40 GPa by controlling nematic flow directionality.
• Identified a design space combining material shaping and mechanical performance.
• Successfully printed LCPs with spatially varying directions and steep curvature variations.
• Created functional objects with stiffness and curvature gradients.

Conclusions:

• The 3D printing method with LCPs enables the creation of complex anisotropic materials with tunable mechanical properties.
• This technique offers potential for lightweight sustainable structures with crack-mitigation strategies.
• The approach opens new possibilities for replicating natural patterns and studying fluid dynamics in engineered materials.