Mechanical tunability of flexoelectricity in elastomers

As a strain-gradient-induced electric polarization, flexoelectricity in dielectric materials is benefiting from its size effect and manipulating strain gradients. Dielectric elastomers (DE) are stretchable with tunable physical and chemical properties. Large deformation enables big strain gradient, highlighting flexoelectricity during electro-mechanical coupling procedures. High and tunable electro-mechanical efficiency is then highly expected in elastomers. In this work, mechanically tunable flexoelectricity in DE is verified with theoretical analysis and experiments. A model is developed to study the mechanism of elastomers under pre-stretch. Experiment verification is applied by measuring the transverse flexoelectric coefficients of polydimethylsiloxane. Flexoelectric coefficient increases with the increase in stretch by one order of magnitude. This work opens up an avenue for tunable flexoelectric applications with stretchable dielectric materials.