Self-Healable, Shape-Programmable and Humidity-Responsive Liquid Crystalline Elastomer Actuators Enabled by Dynamic Covalent Boronic Ester Bonds and Aggregation Induced Emission Luminogens

Abstract

Liquid crystalline elastomers (LCEs) are considered as emerging functional materials that present potentials in fabrication of intelligent soft robots, biomimetic devices and photonic actuators. Here, a new functional liquid crystalline (LC) monomer with dynamic boronic ester group is designed and synthesized. This new molecule has a wide LC phase and polymerizable acrylic double bonds, which facilitates subsequent polymerization to prepare films. The prepared LCEs matrix is intrinsically self-healable and self-weldable. In addition, such material can be used as versatile matrix to be functionalized as diverse devices. By introducing the humidity responsive aggregation-induced emission (AIE) molecules into the LCEs film, which exhibit bright fluorescence at low relative humidity (RH). Finally, copper sulfide (CuS) nanoparticles are doped into the LCEs film to achieve programmable thermal-responsive deformations. This work provides valuable insight for the development of smart soft robots in actuating area.