A Novel Side-Chain Liquid Crystal Elastomer Exhibiting Anomalous Reversible Shape Change

Area of Science:

• Materials Science
• Polymer Chemistry
• Soft Robotics

Background:

• Liquid crystalline elastomers (LCEs) are key materials for stimuli-controlled actuators and soft robots.
• Their function relies on reversible shape changes during the liquid crystalline (LC) to isotropic phase transition.

Purpose of the Study:

• To synthesize and characterize a novel side-chain liquid crystalline polymer (SCLCP) based LCE.
• To investigate the anomalous thermally induced shape-changing behavior of this new LCE.

Main Methods:

• Synthesis of a novel SCLCP-based LCE.
• Mechanical stretching to form a monodomain strip.
• Thermal cycling across the LC-isotropic phase transition to observe shape changes.

Main Results:

• The novel LCE exhibits anomalous behavior: contraction upon heating (LC to isotropic) and elongation upon cooling (isotropic to LC).
• This behavior is observed in both length and width of mechanically stretched monodomain LCE strips.
• The phenomenon arises from the interplay between polymer main chain relaxation and side-group mesogen disordering.

Conclusions:

• A new type of LCE with peculiar thermally responsive shape change has been developed.
• This finding opens avenues for designing LCEs with unique properties.
• Potential applications in advanced actuators and soft robotic systems can be explored.