Collective action and entanglement of magnetically active liquid crystal elastomer ribbons
Abstract
Interactions between active individuals in animal collectives lead to emergent responses that remain elusive in synthetic soft matter. Here, shape-morphing polymers are used to create bio-inspired transient solids that self-assemble with controlled mechanical properties and disassemble on demand. Dilute-suspensions of magnetic, heat-responsive liquid crystal elastomer ribbons mechanically interlock, inducing reversible aggregation. A mathematical model is developed that sheds light on the role of topological mechanisms in aggregation. Aggregation was favored for ribbons with moderate curvature at 25C above crosslinking temperature as compared to flat ribbons or higher curvature ribbons at higher temperatures. The ribbon suspensions reversibly transition between fluid- and solid-like states, exhibiting up to 6 orders-of-magnitude increase in the storage moduli of the entangled aggregates compared with the liquid dispersions. Controlled dissociation is induced by imparting kinetic energy to the individual ribbons at high magnetic field rotation speeds (> 200 RPM). Ribbon shape and the medium in which dissociation occurs were shown to govern disassembly. Imparting dynamic collective behaviors into synthetic systems may enable a range of potential applications from bio-inspired soft robotics to injectable biomaterials.
Keywords
Cite
@article{arxiv.2409.19094,
title = {Collective action and entanglement of magnetically active liquid crystal elastomer ribbons},
author = {Asaf Dana and Christian Benson and Manivannan Sivaperuman Kalairaj and Kayla Hellikson and Sasha M. George and David C. Chimene and Jared A. Gibson and Seelay Tasmim and Phillip A. Kohl and Youli Li and Mustafa K. Abdelrahman and Vishal P. Patil and Taylor H. Ware},
journal= {arXiv preprint arXiv:2409.19094},
year = {2025}
}
Comments
16 pages, 6 figures