Three-dimensional blueprinting of molecular patterns in liquid crystalline polymers
Three-dimensional blueprinting of molecular patterns in liquid crystalline polymers
复制标题
液晶聚合物分子图案的三维蓝图
DOI：
10.1039/d3sm01374j
复制
发表时间：
2024
期刊：
影响因子：
3.4
通讯作者：
Shankar, M. Ravi
中科院分区：
文献类型：
--
作者：
Tabrizi, Mohsen;Clement, J. Arul;Babaei, Mahnoush;Martinez, Angel;Gao, Junfeng;Ware, Taylor H.;Shankar, M. Ravi
利用液晶单体的各向异性抗磁性敏感性和位点选择性光聚合的相互作用，使得能够制造具有高度精细微结构的3D自由形状。在介晶油墨中利用链转移剂提供了一种广泛调节液晶聚合物的机械性能及其对刺激的响应的途径。特别是，1，4-苯二甲乙烷和四溴甲烷的组合显示，使分子顺序的体素化蓝图，同时允许调制的交联密度和机械性能。这些单体的配方允许体素的分辨率接近由表面锚定所定义的相干长度所设定的极限。这些组合物展示了预期的热致响应，同时允许它们用光致变色开关官能化以引发光机械响应。致动应变显示出超越了先前的系统，没有访问链转移剂来调节大分子网络的结构。该系统的测试用例显示，以创建自由形式的致动器，利用高分辨率打印过程中的精细导演图案。这些包括拓扑缺陷，分层结构的光响应夹持器，和仿生飞行器，其飞行动力学可以通过光照射主动调制。
Exploiting the interplay of anisotropic diamagnetic susceptibility of liquid crystalline monomers and site selective photopolymerization enables the fabrication of 3D freeforms with highly refined microstructures. Utilizing chain transfer agents in the mesogenic inks presents a pathway for broadly tuning the mechanical properties of liquid crystalline polymers and their response to stimuli. In particular, the combination of 1,4-benzenedimethanethiol and tetrabromomethane is shown to enable voxelated blueprinting of molecular order, while allowing for a modulation of the crosslink density and the mechanical properties. The formulation of these monomers allows for the resolution of the voxels to approach the limits set by the coherence lengths defined by the anchoring from surfaces. These compositions demonstrate the expected thermotropic responses while allowing for their functionalization with photochromic switches to elicit photomechanical responses. Actuation strains are shown to outstrip that accomplished with prior systems that did not access chain transfer agents to modulate the structure of the macromolecular network. Test cases of this system are shown to create freeform actuators that exploit the refined director patterns during high-resolution printing. These include topological defects, hierarchically-structured light responsive grippers, and biomimetic flyers whose flight dynamics can be actively modulated via irradiation with light.