Rejuvenating liquid crystal elastomers for self-growth.

Area of Science:

• Materials Science
• Polymer Chemistry
• Robotics

Background:

• A unique polymer exhibits self-growth at room temperature without external energy, a key advance for untethered autonomous soft robotics.
• Current self-growing polymers require fresh preparation, limiting practical applications due to the need for monomer synthesis for each use.

Purpose of the Study:

• To develop a method for rejuvenating non-fresh self-growing polymers to enable on-demand regrowth.
• To overcome the limitations of single-use self-growing polymers for practical applications in soft robotics.

Main Methods:

• Utilized solvents to induce swelling, transitioning non-fresh liquid crystal elastomers (LCEs) from a liquid crystal phase to an isotropic phase.
• Introduced a transesterification catalyst via swelling to facilitate topological rearrangements through dynamic covalent bond exchange reactions.
• Demonstrated rejuvenation by erasing growth history, enabling repeated use and regulation via selective swelling.

Main Results:

• Successfully rejuvenated non-fresh LCE samples to an initial state capable of self-growth.
• The rejuvenation process is repeatable and can be controlled through selective swelling.
• The developed strategy allows for the reuse of self-growing LCEs, overcoming previous limitations.

Conclusions:

• A novel strategy for rejuvenating self-growing LCEs has been established using solvents and dynamic covalent bonds.
• This post-modulation method enables on-demand self-growth and repeated use of LCEs.
• The findings promise advanced, reusable materials for cutting-edge soft growing robotics.