Polymer nanocomposites as electrostrictive materials

Abstract

Electronic electroactive polymers (EAPs) are an attractive class of smart materials with many advantages such as lightweight, shape conformability, relatively high strain rates and good energy densities. However, there are major obstacles to their transition to applications. Notably they require high actuation voltages, have low blocked stresses and low operating temperatures. These current limitations are linked to inherent polymer properties such as low dielectric constant and low modulus. Our recent efforts in polymer-based nanocomposites provide new avenues to significantly improve their electromechanical response. In this study, we present experimental evidence of the creation of an electrostrictive response in a PVDF nanocomposite system by addition of small quantities of carbon nanotubes. amorphous polymer nanocomposites Further, we have also demonstrated that the piezoelectric response of nanocomposites can be dramatically enhanced through addition of conductive nanoparticles such as carbon nanotubes without additional weight penalties. Most importantly, these improvements were achieved at much lower actuation voltages, and were accompanied by an increase in both mechanical and dielectric properties. The effective dielectric properties of the nanocomposites indicate an increased polarization as the driving force for this enhancement. Possible causes for the enhanced polarization include contributions from SWNTs, polymer dipoles and SWNTpolymer interaction.