High-Fidelity Replica Molding of Glassy Liquid Crystalline Polymer Microstructures.
High-Fidelity Replica Molding of Glassy Liquid Crystalline Polymer Microstructures.
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DOI：
10.1021/acsami.6b00785
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发表时间：
2016-03
影响因子：
9.5
通讯作者：
Hangbo Zhao;J. Wie;D. Copic;C. Ryan Oliver;Alvin Orbaek White;Sanha Kim;A. J. Hart
中科院分区：
文献类型：
--
作者：
Hangbo Zhao;J. Wie;D. Copic;C. Ryan Oliver;Alvin Orbaek White;Sanha Kim;A. J. Hart
液晶聚合物最近被设计成具有复杂的宏观形状适应性，包括光学和热驱动的弯曲、自维持振荡、扭转运动和三维折叠。这些新型材料的小型化对于加工条件的基础研究和形状变化微器件的发展都具有重要意义。在这里，我们提出了一种可扩展的方法，用于玻璃液晶聚合物网络（LCNs）的高保真复制成型，通过真空辅助复制成型，以及磁场诱导的分子排列控制。我们发现无氧环境是建立高保真成型与低表面粗糙度的必要条件。制作了相同的同向异性和多畴LCN微结构阵列，以评估分子排列对弹性模量的影响（E = 1.48 GPa与E = 0.54 GPa相比），并通过高分辨率边缘运动跟踪使用侧视成像来量化单个LCN微柱的可逆热致动。这项研究的方法和结果将与液晶聚合物化学的未来发展协同作用，并可能使刺激响应表面的可扩展制造成为可能，包括微流体、可调光学和具有可切换润湿和粘附性的表面。
Liquid crystalline polymers have recently been engineered to exhibit complex macroscopic shape adaptivity, including optically- and thermally driven bending, self-sustaining oscillation, torsional motion, and three-dimensional folding. Miniaturization of these novel materials is of great interest for both fundamental study of processing conditions and for the development of shape-changing microdevices. Here, we present a scalable method for high-fidelity replica molding of glassy liquid crystalline polymer networks (LCNs), by vacuum-assisted replica molding, along with magnetic field-induced control of the molecular alignment. We find that an oxygen-free environment is essential to establish high-fidelity molding with low surface roughness. Identical arrays of homeotropic and polydomain LCN microstructures are fabricated to assess the influence of molecular alignment on the elastic modulus (E = 1.48 GPa compared to E = 0.54 GPa), and side-view imaging is used to quantify the reversible thermal actuation of individual LCN micropillars by high-resolution tracking of edge motion. The methods and results from this study will be synergistic with future advances in liquid crystalline polymer chemistry, and could enable the scalable manufacturing of stimuli-responsive surfaces for applications including microfluidics, tunable optics, and surfaces with switchable wetting and adhesion.