Liu Mingzhu, Jin Lishuai, Yang Shengsong, Wang Yuchen, Murray Christopher B, Yang Shu
Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA.
Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA.
Adv Mater. 2023 Feb;35(5):e2208613. doi: 10.1002/adma.202208613. Epub 2022 Dec 20.
Liquid crystalline elastomers (LCEs) with intrinsic molecular anisotropy can be programmed to morph shapes under external stimuli. However, it is difficult to program the position and orientation of individual mesogenic units separately and locally, whether in-plane or out-of-plane, since each mesogen is linked to adjacent ones through the covalently bonded polymer chains. Here, dually responsive, spindle-shaped micro-actuators are synthesized from LCE composites, which can reorient under a magnetic field and change the shape upon heating. When the discrete micro-actuators are embedded in a conventional and nonresponsive elastomer with programmed height distribution and in-plane orientation in local regions, robust and complex shape morphing induced by the cooperative actuations of the locally distributed micro-actuators, which corroborates with finite element analysis, are shown. The spatial encoding of discrete micro-actuators in a nonresponsive matrix allows to decouple the actuators and the matrix, broadening the material palette to program local and global responses to stimuli for applications including soft robotics, smart wearables, and sensors.
具有固有分子各向异性的液晶弹性体（LCE）可在外部刺激下被编程以改变形状。然而，单独且局部地对单个介晶单元的位置和取向进行编程是困难的，无论是面内还是面外，因为每个介晶通过共价键合的聚合物链与相邻介晶相连。在此，由LCE复合材料合成了双响应纺锤形微致动器，其可在磁场下重新取向并在加热时改变形状。当离散的微致动器嵌入具有局部区域编程高度分布和面内取向的传统非响应弹性体中时，展示了由局部分布的微致动器协同驱动引起的稳健且复杂的形状变形，这与有限元分析结果相符。在非响应基质中对离散微致动器进行空间编码可使致动器与基质解耦，拓宽了材料选择范围，以便对包括软机器人、智能可穿戴设备和传感器在内的应用中的局部和全局刺激响应进行编程。
