Rapidly and Repeatedly Reprogrammable Liquid Crystalline Elastomer via a Shape Memory Mechanism

Realization of muscle-like actuation for a liquid crystal elastomer (LCE) requires mesogen alignment, which is typically achieved/fixed chemically during the synthesis. Post-synthesis regulation of the alignment in a convenient and repeatable manner is highly desirable yet challenging. Here, a dual-phase LCE network is designed and synthesized with a crystalline melting transition above a liquid crystalline transition. The crystalline phase can serve as an alignment frame to fix any mechanical deformation via a shape memory mechanism, leading to corresponding mesogen alignment in the liquid crystalline phase. The alignment can be erased by melting, which can be the starting point for reprogramming. This strategy that relies on a physical shape memory transition for mesogen alignment permits repeated reprogramming in a timescale of seconds, in stark contrast to typical methods. It further leads to unusual versatility in designing 3D printed LCE with unlimited programmable actuation modes.

Automated summary

In this study, a dual-phase LCE network was designed and synthesized to achieve mesogen alignment by utilizing a shape memory mechanism in the crystalline phase. The alignment can be erased through melting, enabling repeated reprogramming and offering exceptional versatility in designing 3D printed LCE.