Abstract Swollen nematic elastomers can deform under an applied electric field due to the electro-opto-mechanical coupling effect. This unique coupling mechanism causes the nematic elastomer to exhibit larger deformations under weak electric fields as compared to many conventional dielectric elastomers. Further, the electric-field induced deformations can be controlled by proper design of the initial liquid crystal director. Based on a simple electro-mechanical-director coupled model under small strain assumption, finite element simulations are conducted for beam-shaped thin strip samples with orientation gradient initially. Approximate analytical solutions are obtained for the electric potential, director reorientations, stress, and strain under weak electric fields. Using the first- order shear strain beam theory, the analytical solutions for the bending deflections are determined for beams with various boundary conditions, and they are only governed by the spontaneous curvature and the average transversal spontaneous shear resulting from the spontaneous strains induced by the applied electric fields. Optimization of the electric-field induced bending curvature leads to linearly-varying director distributions, which have much larger bending curvatures than that exhibited by the most commonly studied splay-bend distribution. Moreover, we demonstrate that bending shapes strongly depend on the orientational distribution of the director. Thus, a proper design can be used to effectively control the electric-field induced deformation and bending. Overall, we believe that our study is potentially useful to create desired and optimized bending for electrically-triggered sensors and actuators.

中文翻译：

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具有取向梯度的向列弹性体条中的电场诱导变形和弯曲

摘要 由于电光机械耦合效应，膨胀的向列弹性体在外加电场作用下会发生变形。与许多传统介电弹性体相比，这种独特的耦合机制导致向列弹性体在弱电场下表现出更大的变形。此外，电场引起的变形可以通过初始液晶指向矢的适当设计来控制。基于小应变假设下的简单机电导向器耦合模型，对初始具有取向梯度的梁状薄带样品进行了有限元模拟。获得了弱电场下的电势、指向矢重定向、应力和应变的近似解析解。使用一阶剪应变梁理论，弯曲挠度的解析解是针对具有各种边界条件的梁确定的，它们仅受自发曲率和由施加的电场引起的自发应变产生的平均横向自发剪切控制。电场诱导弯曲曲率的优化导致线性变化的指向矢分布，其弯曲曲率比最常研究的张开弯曲分布所表现出的弯曲曲率大得多。此外，我们证明弯曲形状强烈依赖于指向矢的取向分布。因此，可以使用适当的设计来有效地控制电场引起的变形和弯曲。全面的，