Ionic polarization in bending-electrostrictive response of polyurethane films

Effects of ionic polarization on hysteresis in the bending-electrostrictive response of polyurethane films are reported. The relation between the ionic polarization and charge injection from the anode was investigated using a model system. As a result, taking into account an internal electric field inside the film, the effects could be reasonably explained as follows. When the ionic polarization weakened the internal field near the anode, the charge injection was suppressed, resulting in a slow response. On the other hand, when the polarization strengthened it, the charge injection was promoted, which led to a quick response. (C) 2001 American Institute of Physics.