Enhanced Actuation Response of Nafion-Based Ionic Polymer Metal Composites by Doping BaTiO₃ Nanoparticles

Nafion-based composite membranes by doping BaTiO 3 nanoparticles were prepared to fabricate high-performance ionic polymer metal composite (IPMC) actuators. BaTiO 3 /Nafion nanocomposites were evaluated in terms of their static mechanical properties, water uptake, surface resistivity, electrochemical impedance, and actuation behaviors. The results show that the BaTiO 3 /Nafion-based IPMCs have higher ionic conductivity and capacitance and better actuator behavior in comparison with the pure Nafion-based counterpart. The membrane with 3 wt % BaTiO 3 nanoparticles exhibits the best overall property under a 3 V dc or ac voltage excitation: exceptional deflections are obtained up to 101.4% under the dc input and 250% under the ac input at a frequency of 1 Hz; the blocking force is increased over 375% at the dc input, in sharp contrast to the pure Nafion sample. The improvements are attributed to the double-layer electrostatic effect which is induced by the broad dispersion of penetrated nanoparticles into electrodes. This study provides an innovative approach to develop high-performance IPMC actuators.