Barnes Morgan, Cetinkaya Sueda, Ajnsztajn Alec, Verduzco Rafael
Department of Materials Science and NanoEngineering, Rice University, Houston, Texas, 77005, USA.
Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas, 77005, USA.
Soft Matter. 2022 Jul 13;18(27):5074-5081. doi: 10.1039/d2sm00480a.
Liquid crystal elastomers are stimuli-responsive, shape-shifting materials. They typically require high temperatures for actuation which prohibits their use in many applications, such as biomedical devices. In this work, we demonstrate a simple and general approach to tune the order-to-disorder transition temperature () or nematic-to-isotropic transition temperature () of LCEs through variation of the overall liquid crystal mass content. We demonstrate reduction of the in nematic LCEs through the incorporation of non-mesogenic linkers or the addition of lithium salts, and show that the varies linearly with liquid crystal mass content over a broad range, approximately 50 °C. We also analyze data from prior reports that include three different mesogens, different network linking chemistries, and different alignment strategies, and show that the linear trend in with liquid crystal mass content also holds for these systems. Finally, we demonstrate a simple approach to quantifying the maximum actuation strain through measurement of the soft elastic plateau and demonstrate applications of nematic LCEs with low s, including the first body-responsive LCE that curls around a human finger due to body heat, and a fluidic channel that directionally pumps liquid when heated.
液晶弹性体是对刺激有响应的、可改变形状的材料。它们通常需要高温来驱动，这限制了它们在许多应用中的使用，比如生物医学设备。在这项工作中，我们展示了一种简单且通用的方法，通过改变液晶的总质量含量来调节液晶弹性体的有序-无序转变温度（ ）或向列相-各向同性转变温度（ ）。我们通过引入非介晶连接体或添加锂盐来证明向列相液晶弹性体中 的降低，并表明在大约50°C的宽范围内， 随液晶质量含量呈线性变化。我们还分析了先前报告中的数据，这些数据包括三种不同的介晶、不同的网络连接化学和不同的取向策略，并表明 随液晶质量含量的线性趋势在这些体系中也成立。最后，我们展示了一种通过测量软弹性平台来量化最大驱动应变的简单方法，并展示了具有低 的向列相液晶弹性体的应用，包括第一个因人体热量而围绕人手指卷曲的身体响应型液晶弹性体，以及一个加热时能定向泵送液体的流体通道。
