Low Voltage-Driven, High Frequency-Responsive Actuators Utilizing Ion-Conductive Liquid Crystal-Polymer Composites

Abstract

We present the development of free-standing composite electrolyte films based on ionic liquid crystal and polymers, aimed at achieving high-frequency response electromechanical actuators. Our approach involves designing novel layered ionic liquid crystals by complexing mesomorphic phosphates with lithium salts or ionic liquids through ion-dipole interactions or hydrogen bonds. These liquid crystals, when combined with vinyl polymers, yield non-flammable composite membranes with microphase-segregated structures, exhibiting room-temperature ionic conductivities of approximately 10-4 S/cm. The composite actuators, integrated with PEDOT:PSS electrodes, demonstrate bending responses at frequencies up to 130 Hz, driven by the electric double layer formation and the redox reaction of PEDOT. Additionally, we showcase a ring-shaped haptic interface utilizing these soft actuators to provide tactile sensations upon contact with fingers.