Lin Xueyan, Saed Mohand O, Terentjev Eugene M
Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE, UK.
Soft Matter. 2021 Jun 2;17(21):5436-5443. doi: 10.1039/d1sm00432h.
Fibrous liquid crystalline elastomers (LCE) are an attractive variant of LCE-based actuators due to their small thickness, leading to faster response times to stimuli, as well as the increased mechanical strength. Fabrication of LCE fibers has been attempted by various research groups using electro-spinning or micro-fluidic techniques, without much success. Here we propose an alternative way to achieve single-step continuous spinning LCE fibers in a more scalable and robust way, based on a liquid-ink 3D printer. We demonstrate this technique in our home-made device by dynamically extruding/stretching liquid crystalline oligomer mixed with photo-reactive cross-linker, to fix the aligned network under UV light after extrusion. The report also describes a protocol for material synthesis and identifies optimal conditions for the stable fiber spinning process. Microns-thick LCE fibers with two different compositions have been successfully spun, and demonstrated enhanced mechanical properties with the inherited thermal-actuation capability. This technique also demonstrates the potential to fine-tune the mechanical properties of fibers to enable further development in fiber-based LCE applications.
纤维状液晶弹性体（LCE）是基于LCE的致动器的一种有吸引力的变体，因为它们厚度小，导致对刺激的响应时间更快，并且机械强度增加。各个研究小组尝试使用静电纺丝或微流体技术制造LCE纤维，但成效不大。在此，我们提出了一种基于液体油墨3D打印机的更具可扩展性和稳健性的单步连续纺丝LCE纤维的替代方法。我们在自制设备中展示了该技术，通过动态挤出/拉伸与光反应性交联剂混合的液晶低聚物，在挤出后在紫外线下固定排列的网络。该报告还描述了材料合成方案，并确定了稳定纤维纺丝过程的最佳条件。成功纺出了具有两种不同成分的微米级厚LCE纤维，并展示了增强的机械性能以及继承的热驱动能力。该技术还展示了微调纤维机械性能以推动基于纤维的LCE应用进一步发展的潜力。
