Solvent-Assisted 4D Programming and Reprogramming of Liquid Crystalline Organogels

Area of Science:

• Materials Science
• Polymer Chemistry
• Soft Matter Physics

Background:

• Liquid crystalline networks (LCNs) exhibit shape morphing capabilities controlled by molecular ordering.
• Current methods for shape control in LCNs are often fixed after initial programming or involve permanent structural changes.
• Dynamic covalent bonds allow for reprogramming but can alter network integrity.

Purpose of the Study:

• To introduce an entropic approach for programming complex shapes in LCNs.
• To enable on-demand shape erasure and reprogramming of LCNs.
• To decouple network synthesis from molecular alignment for greater flexibility.

Main Methods:

• Utilizing directed solvent evaporation from an isotropic LCN organogel to program shapes.
• Employing different deformation modes during solvent evaporation to control final shape.
• Applying digital light processing (DLP) printing for LCN fabrication.

Main Results:

• Demonstrated the ability to program complex shapes through controlled solvent evaporation.
• Showcased on-demand erasure and reprogramming of shapes from the same LCN material.
• Achieved complex origami/kirigami structures and 4D shape morphing with high spatial and temporal control.

Conclusions:

• The entropic approach using directed solvent evaporation offers a versatile method for LCN shape programming.
• Decoupling network synthesis and alignment simplifies LCN fabrication and expands material possibilities.
• This technique enables advanced applications in programmable materials and 4D printing.