Polyelectrolyte hydrogels as electromechanical transducers

Abstract

Polyelectrolyte hydrogels consist of cross linked, charged polymer chains swollen in water or another highly dielectric solvent. They represent a salt solution in which ions of one type (usually, anions) are bound to the polymer backbone, while the other ions (usually, cations) are freely mobile in the solvent. This difference in mobility brings about interesting electromechanical properties. In this contribution, we discuss our recent research concerning the application of polyelectrolyte hydrogels as sensor materials. A new indentation method for the quantitation of the electromechanical effect in polyelectrolyte hydrogels has been developed, and used for a systematic study of the relationship between the spatial charge density and the electromechanical coupling constant. Prototypes of microfluidic devices applying such gels as pressure transducers have been built, and preliminary experimental data of their performance is presented.