Mechanically Tough Micellar Cubic Liquid-Crystalline Polymer Electrolytes for Electromechanical Actuators

Abstract

This study presents a novel micellar cubic ionic liquid-crystalline polymer electrolyte, featuring an alignment-free spherical structure with unimpeded 3D ionic pathways, aimed at enhancing the performance of an ionic electroactive polymer actuator. The development involved creating a mechanically tough and high ion-conductive cubic polymer film through the self-assembly of a wedge-shaped vinyl imidazolium salt and an imidazolium ionic liquid, followed by in situ photopolymerization. The 300 µm-thick-trilayer films, consisting of the cubic polymer electrolyte sandwiched between poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) electrodes, exhibit remarkable capabilities. These include bearing substantial loads of 4 g with a high blocking force under a DC voltage of 2 V, achieving a high bending strain of 0.63% under a low input voltage (±2 V, 0.1 Hz), and boasting a maximum response frequency of 70 Hz. These properties position the material for potential applications in soft robots and tactile sensing devices.