Crystals, Vol. 16, Pages 16: Electric-Field Actuation of Liquid Crystalline Elastomer Films

Crystals doi: 10.3390/cryst16010016

Authors:
Mizuho Sawada
Kosuke Kaneko
Kiyomi Fuchigami
Kimiyoshi Kaneko
Hirohiko Washiya
Tomonori Hanasaki

Liquid crystal elastomers (LCEs) are soft, stimuli-responsive materials capable of converting molecular-scale reorientation of mesogenic groups into macroscopic, reversible deformations. In this study, film-shaped LCEs were fabricated via a thiol–ene click reaction and characterized under varying electric-field strengths and tensile loads. The LCEs exhibited pronounced soft elasticity and large, reversible strains due to reorientation of mesogenic groups, in contrast to non-mesogenic elastomers. Dynamic viscoelastic measurements revealed fully reversible changes in storage modulus upon electric-field application, highlighting the critical role of mesogenic group alignment in electromechanical actuation. Electric-field-induced contraction increased with field strength and decreased with tensile load, reaching a maximum of 15% under minimal load, with additional enhancement resulting from mesogenic group reorientation along the thickness direction. Notably, unlike conventional light- or temperature-driven actuation, which is often limited by slow molecular relaxation or heat diffusion, the electric-field-driven LCE exhibited rapid, fully reversible deformation. These findings demonstrate the potential of electric-field-responsive LCEs for applications requiring fast, controllable, and large-strain actuation, and provide insights into the interplay between mesogenic group orientation, mechanical loading, and external stimuli in designing efficient soft actuators.

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Mizuho Sawada www.mdpi.com