Polymeric piezoelectric cantilever and tubular actuators

Electroactive polymers (EAPs) have attracted a great deal of attention in the last decade due to their unique properties that are applicable to many advanced applications. The present work aims to study the materials-property relationship of this class of materials, and thus facilitate the implementation of EAPs in more applications. The present work investigated the feasibility of adapting cantilever and tubular configurations to the polymeric piezoelectric actuators. The polarization and displacement of samples (fabricated from Poly(Vinyldene fluoride-trifluroethylene) [P(VDF-TrFE)] thin film) were measured under both dynamic and static driving conditions. The polarization loops for all the samples exhibit little hysteresis under weak field and the polarization changes linearly with voltage for most samples. The frequency-dependent polarization behavior is consistent with the previous reported work. The displacements for both cantilever and tubular samples are also noted to be in agreement with the theoretical prediction. Significant displacement (1079 mu m) was achieved for samples, even under weak field (60 MV/m). In summary, the results have suggested that the relationship between geometric variables and the performance is also applicable to polymeric materials. Thus, the constitutive relationship can also be applied as a guideline for designing and optimizing the polymeric actuators beyond P(VDF-TrFE) copolymer materials. Copyright (C) 2009 John Wiley & Sons, Ltd.