Multiple shapes from a single nematic elastomer sheet activated via patterned illumination
Multiple shapes from a single nematic elastomer sheet activated via patterned illumination
复制标题
DOI：
10.1209/0295-5075/ac9e19
复制
发表时间：
2022-11-01
期刊：
影响因子：
1.8
通讯作者：
Biggins, J. S.
中科院分区：
文献类型：
--
作者：
Giudici, A.;Clement, A.;Biggins, J. S.
- 液晶弹性体 (LCE) 在热或光刺激下会发生较大的单轴收缩。 LCE 片材通常以空间图案化的收缩方向制造，这可以将片材雕刻成高斯曲面。在这里，我们考虑 LCE 片受图案化刺激强度的影响，从而控制收缩强度。我们表明，此类图案也可以雕刻复杂的表面，但其优点是可以在同一样品中顺序实现任意多个表面，从而打破微观结构和形状之间的联系。我们首先考虑单域 LCE，其中一些区域被激活，而另一些区域则不被激活。我们讨论如何兼容地连接驱动区域和非驱动区域，并使用此设计规则生成锥体、反锥体、锥体阵列和滚动双带的图案。我们通过弹性壳模拟对这些图案进行数值验证，并通过图案化光化学驱动进行实验演示。其次，我们考虑具有由径向变化的刺激驱动的方位角导向器轮廓的 LCE 盘。我们从理论上和数值上展示了如何设计刺激轮廓来雕刻任何旋转表面。这种可重新配置的驱动为触觉、机器人和运动提供了诱人的可能性。
- Liquid crystal elastomers (LCEs) undergo a large uniaxial contraction upon thermal or optical stimulation. LCE sheets are often fabricated with a spatially patterned direction of contraction, which can sculpt the sheet into a Gauss-curved surface. Here, we instead consider LCE sheets subject to patterned stimulation intensity, leading to a control of contraction strength. We show such patterns may also sculpt a complex surface, but with the advantage that arbitrarily many surfaces may be achieved sequentially in the same sample, thus breaking the link between microstructure and shape. We first consider a monodomain LCE in which some regions are actuated and others are not. We discuss how to join actuated and unactuated regions compatibly, and use this design rule to generate patterns for cones, anti-cones, arrays of cones and a rolling bi-strip. We validate the patterns numerically via elastic shell simulations and demonstrate them experimentally via patterned photo-chemical actuation. Secondly, we consider an LCE disk with an azimuthal director profile actuated by a radially varying stimulus. We show, theoretically and numerically, how to design a stimulation profile to sculpt any surface of revolution. Such re-configurable actuation offers enticing possibilities for haptics, robotics and locomotion.