Improving Dielectric Constant of Polymers through Liquid Electrolyte Inclusion

Abstract Different from the traditional ways for enhancing the dielectric properties of polymers by compositing with rigid electronic conductors, here an alternative strategy is reported via introducing ionically conductive liquid electrolytes as functional fillers. Dielectric constant has significantly improved (up to 600%) by liquid electrolyte inclusions in an elastomer matrix. Moreover, by taking advantage of the inherent transparency of liquid electrolyte fillers, high transparency, good stretchability, and high dielectric constant are achieved simultaneously. Using the composite elastomer, the fabrication of highly sensitive strain sensor is demonstrated with 5–6 times higher sensitivity than the pristine elastomer, and flexible electroluminescent device with greatly lowed driving voltage. The strategy provides new opportunities for novel electroactive polymers, including flexible touchscreen panels and displays, biomimetic soft machines, and smart optics.