Liquid crystalline elastomers (LCEs) are crosslinked polymer networks that combine the elastic properties of rubber with the anisotropic properties of liquid crystals. Multifunctionality and responsivity can be programmed into LCEs by patterning their local orientation, which is difficult to achieve in other monolithic material systems. Advances in the synthesis and alignment of LCEs have paved the way for their functional integration in robotics, optics, consumer products, energy and healthcare devices. In this Review, we discuss recent advances in materials chemistry and processing that have contributed to the resurgence in LCE research. We examine the mechanical response of LCEs to stimuli and survey approaches for mechanical alignment, surface-enforced alignment, field-induced alignment and rheological alignment. The Review concludes with an over-the-horizon outlook discussing current challenges and emerging research opportunities.

液晶弹性体 (LCE) 是交联聚合物网络，它结合了橡胶的弹性特性和液晶的各向异性特性。通过图案化 LCE 的局部方向，可以将多功能性和响应性编程到 LCE 中，这在其他单片材料系统中很难实现。LCE 合成和对齐方面的进展为其在机器人、光学、消费产品、能源和医疗保健设备中的功能集成铺平了道路。在这篇评论中，我们讨论了材料化学和加工方面的最新进展，这些进展有助于 LCE 研究的复兴。我们检查了 LCE 对刺激的机械响应，以及机械对准、表面强制对准、场诱导对准和流变对准的调查方法。