Thermomechanical liquid crystalline elastomer capillaries with biomimetic peristaltic crawling function

Area of Science:

• Materials Science
• Biomimetic Engineering
• Soft Robotics

Background:

• Liquid crystalline elastomers (LCEs) offer unique thermomechanical properties for advanced device fabrication.
• Biomimetic locomotion is a key area of research for developing novel actuators and robots.
• Mimicking natural movements like peristalsis can lead to efficient and adaptable artificial systems.

Purpose of the Study:

• To fabricate LCE capillaries with biomimetic peristaltic function for the first time.
• To mimic the peristaltic crawling locomotion of earthworms using LCE technology.
• To explore the potential applications of these LCE capillaries in miniature robots and actuators.

Main Methods:

• Fabrication of side-on LCE capillaries within specifically designed LC cells with polyimide alignment layers.
• Utilizing photoinitiated polymerization and crosslinking of monomers and crosslinkers.
• Characterization of thermomechanical properties and observation of peristaltic crawling locomotion under controlled heating.
• Finite elemental analysis (FEA) simulation to elucidate the crawling mechanism.

Main Results:

• LCE capillaries exhibited predominant mesogen orientation along the capillary axis due to alignment layers.
• Reversible thermomechanical contraction (16% length) and expansion (12% diameter) were observed during phase transition.
• Successful realization of reversible peristaltic crawling locomotion with a speed of 0.31 mm s^-1.
• A five-stage motion model was established to explain the crawling mechanism and its correlation with earthworm locomotion.

Conclusions:

• The study successfully fabricated LCE capillaries with biomimetic peristaltic crawling function.
• The alignment layers play a crucial role in controlling the LCE's thermomechanical response and locomotion.
• These LCE capillaries show significant promise for applications in biomimetic miniature robots and actuators.