Blueprinting Photothermal Shape-Morphing of Liquid Crystal Elastomers
Blueprinting Photothermal Shape-Morphing of Liquid Crystal Elastomers
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DOI：
10.1002/adma.202000609
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发表时间：
2020-04-01
影响因子：
29.4
通讯作者：
Hayward, Ryan C.
中科院分区：
文献类型：
--
作者：
Kuenstler, Alexa S.;Chen, Yuzhen;Hayward, Ryan C.
液晶弹性体（LCE）是一个有吸引力的平台，动态形状变形，由于它们的能力，迅速经历大的变形。虽然最近的工作集中在图案化的指向矢取向场，以实现所需的目标形状，这种策略不能推广到材料系统的高分辨率的表面对准是不切实际的。而不是编程的各向异性变形的局部取向，一个替代的战略，通过编程的拉伸比的大小在一个薄的LCE片与恒定的导演方向在这里规定的形状变形。通过在空间上图案化金纳米颗粒的浓度，均匀的照明导致光热热生成的梯度，因此导致空间上不均匀的变形轮廓，其将平面膜的平面外屈曲驱动成可预测的3D形状。实验实现的形状与有限元模拟和几何预测系统的变形幅度单向变化密切一致。最后，证明了通过独立图案片的均匀照明驱动实现复杂振荡运动的可能性。
Liquid crystal elastomers (LCEs) are an attractive platform for dynamic shape-morphing due to their ability to rapidly undergo large deformations. While recent work has focused on patterning the director orientation field to achieve desired target shapes, this strategy cannot be generalized to material systems where high-resolution surface alignment is impractical. Instead of programming the local orientation of anisotropic deformation, an alternative strategy for prescribed shape-morphing by programming the magnitude of stretch ratio in a thin LCE sheet with constant director orientation is developed here. By spatially patterning the concentration of gold nanoparticles, uniform illumination leads to gradients in photothermal heat generation and therefore spatially nonuniform deformation profiles that drive out-of-plane buckling of planar films into predictable 3D shapes. Experimentally realized shapes are shown to agree closely with both finite element simulations and geometric predictions for systems with unidirectional variation in deformation magnitude. Finally, the possibility to achieve complex oscillatory motion driven by uniform illumination of a free-standing patterned sheet is demonstrated.