Design and printing of embedded conductive patterns in liquid crystal elastomer for programmable electrothermal actuation

Here we developed a novel strategy to predict and control the electrothermal property and deformation pattern of electrically stimuli-responsive structures by printing programmable conductive patterns inside liquid crystal elastomer (LCE). It was found that the printed conductive patterns had excellent electrothermal performance and can be heated up to 120°C within 12 s under the stimulus of an applied voltage. By controlling the width and spacing of the conductive lines, the electrothermal temperature of bilayer LCE structures can be regionally modulated, which subsequently determines the structural deformation for desired actuation. A finite element simulation method was established to accurately predict the effect of different conductive pattern design on the final deformation profiles, which showed a good consistence to the experimental results. The presented strategy exhibited unique capability in fabricating conductive pattern-embedded electrothermal structures for various programmable deformations like wing flapping, soft robot crawling and finger bending.