Moisture and electric coupling stimulated ionic polymer actuator with superior deformation behavior

Abstract

To date, water-based ionic polymer metal composite (IPMC) is just regarded as a kind of electroactive material, whereas humidity is traditionally regarded as a disadvantageous factor, the change of which negatively influences the performance of the IPMC. However, the deformation of the IPMC is greatly sensitive to ambient humidity, and can be enhanced dramatically by changing the humidity. In this study, a novel actuation mode is proposed to control the deformation behavior of IPMC by employing moisture as an independent or collaborative incentive source together with the electric field. The deformation is continuously recorded under electric field and electric field-moisture coupling stimulus. These results are consistent with the view that the bending properties of the IPMC are a result of the balance of osmotic pressure and electrostatic stress in the membrane, which is greatly dependent on the change of humidity. Therefore, development of the coupling-drive mode is of great significance for the guidance of material design and application for the IPMC.