Nanostructured liquid-crystalline polymer films for ionic actuators: self-assembly of photopolymerizable ionic itaconate with an ionic liquid

Abstract

The development of nanostructured polymers that create organized ion-transport pathways represents a promising approach for achieving efficient electromechanical conversion. To this end, a durable layered liquid-crystalline (LC) polymer film has been created through the self-assembly of a novel photopolymerizable itaconate derivative containing a non-volatile ionic liquid and a poly(ethylene glycol)-based crosslinker. The LC sample is aligned using a shear force and then in situ photopolymerized. The shear-aligned layered structure exhibits enhanced ion transport and Young's modulus. These robust ionic LC electrolytes can be applied to soft actuators, as evidenced by the remarkably high bending strain and force generation of the layered actuator, despite its low ionic liquid content. This study opens up new possibilities for electromechanical energy conversion in next-generation soft robots.