An Amino-Yne Click Chemistry Approach for Multi-Responsive Liquid Crystal Elastomer Actuators

Area of Science:

• Materials Science
• Polymer Chemistry
• Soft Robotics

Background:

• Liquid Crystal Elastomers (LCEs) are advanced materials known for their stimulus-responsive actuation.
• Developing efficient and versatile methods for synthesizing multi-responsive LCE actuators remains a key challenge in materials science.

Purpose of the Study:

• To introduce a novel, rapid, and efficient strategy for preparing multi-responsive LCE actuators at ambient temperature.
• To explore the potential of the amino-yne click reaction for creating tunable and programmable soft actuators.

Main Methods:

• Utilized a spontaneous amino-yne click reaction for cross-linking poly(β-amino ester) liquid crystal oligomers with a dipropiolate-functionalized cross-linker.
• Achieved alignment and locking of the LCE network via dynamic transesterification at 30 °C.
• Investigated thermal, light, and acid-triggered (water-driven) actuation responses.

Main Results:

• Successfully prepared multi-responsive LCE actuators exhibiting reversible and reproducible thermal and light-induced actuation.
• Demonstrated that actuation tension and kinetics are tunable by adjusting cross-linker content.
• Showcased acid-triggered, water-driven actuation and fabricated a star-shaped soft actuator with programmable modes.

Conclusions:

• The amino-yne click reaction provides a facile and efficient route to multi-responsive LCE actuators.
• The dynamic nature of the cross-links allows for complex molecular orientation and programmable actuation.
• This approach opens new possibilities for designing advanced soft robotic systems and adaptive materials.