Processing advances in liquid crystal elastomers provide a path to biomedical applications
Processing advances in liquid crystal elastomers provide a path to biomedical applications
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液晶弹性体的加工进展为生物医学应用提供了途径
DOI：
10.1063/5.0021143
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发表时间：
2020-10-14
影响因子：
3.2
通讯作者：
Ware, Taylor H.
中科院分区：
文献类型：
--
作者：
Ambulo, Cedric P.;Tasmim, Seelay;Ware, Taylor H.
液晶弹性体(LCEs)是一类对环境变化具有可逆形状变化的刺激响应型聚合物。LCEs的形状变化可以在加工过程中通过在交联化之前取向液晶相来编程。已经开发出的一套加工技术已经导致了无数具有不同形状变化行为和机械性能的LCE。通过机械应变来对准LCE可以产生能够适中输出力的大型单轴致动器。利用磁场来控制LCE微结构内的对准。通过薄膜内的表面对准技术，可以产生弯曲、扭曲和圆锥等平面外变形。4D打印工艺已经出现，能够制造厘米级的、具有复杂对准的3D LCE结构。加工技术还在很大程度上决定了LCE的潜在应用。例如，4D打印能够制造能够复制人类肌肉产生的力的LCE致动器。利用表面对准技术，LCE薄膜可以设计为用作可拉伸电子设备的涂层或衬底。新工艺和策略的发展为LCE在生物医学设备设计中的应用开辟并加强了道路。
Liquid crystal elastomers (LCEs) are a class of stimuli-responsive polymers that undergo reversible shape-change in response to environmental changes. The shape change of LCEs can be programmed during processing by orienting the liquid crystal phase prior to crosslinking. The suite of processing techniques that has been developed has resulted in a myriad of LCEs with different shape-changing behavior and mechanical properties. Aligning LCEs via mechanical straining yields large uniaxial actuators capable of a moderate force output. Magnetic fields are utilized to control the alignment within LCE microstructures. The generation of out-of-plane deformations such as bending, twisting, and coning is enabled by surface alignment techniques within thin films. 4D printing processes have emerged that enable the fabrication of centimeter-scale, 3D LCE structures with a complex alignment. The processing technique also determines, to a large extent, the potential applications of the LCE. For example, 4D printing enables the fabrication of LCE actuators capable of replicating the forces generated by human muscles. Employing surface alignment techniques, LCE films can be designed for use as coatings or as substrates for stretchable electronics. The growth of new processes and strategies opens and strengthens the path for LCEs to be applicable within biomedical device designs.