Shape changes in chemoresponsive liquid crystal elastomers
Shape changes in chemoresponsive liquid crystal elastomers
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DOI：
10.1016/j.snb.2016.09.004
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发表时间：
2017-03-01
影响因子：
8.4
通讯作者：
Ware, Taylor H.
中科院分区：
文献类型：
--
作者：
Boothby, Jennifer M.;Kim, Hyun;Ware, Taylor H.
液晶弹性体是有序的聚合物，其响应于许多刺激（包括热、光和溶剂）而经历可逆的各向异性形状变化。在这项研究中，我们设计的液晶弹性体，致动轴向和扭转的化学刺激。我们表征的单轴取向的液晶弹性体膜暴露于各种不同质量的化学刺激的响应。在每种溶剂中，存在沿着配向方向的收缩和在垂直方向上的膨胀。扭转致动通过在液晶弹性体的厚度上图案化扭曲排列而产生。这些分层图案化的材料在化学蒸气中以超过200度/mm的扭曲可逆地从平面转变为螺旋。该响应稳定至少100个循环。最终，这种化学反应与机械不稳定性相结合，使高扭转扭转致动器的峰值速度几乎为400 RPM。(C)© 2016 Elsevier B. V.版权所有。
Liquid crystal elastomers are ordered polymers that undergo reversible, anisotropic shape change in response to a number of stimuli, including heat, light, and solvent. In this study, we design liquid crystal elastomers that actuate both axially and torsionally in response to chemical stimuli. We characterize the response of uniaxially-aligned liquid crystal elastomer films exposed to a variety of chemical stimuli of varying quality. In each solvent, there is a contraction along the alignment direction paired with an expansion in the perpendicular directions. Torsional actuation is generated by patterning a twisted alignment through the thickness of the liquid crystal elastomer. These hierarchically-patterned materials reversibly transition from flat to helical with over 200 degrees/mm of twist in chemical vapor. This response is stable for at least 100 cycles. Ultimately, this chemoresponse is combined with mechanical instability to make high-twist torsional actuators with peak velocities of almost 400 RPM. (C) 2016 Elsevier B.V. All rights reserved.