Fast actuation properties of several typical IL-based ionic electro-active polymers under high impulse voltage

Abstract

Slow deformation is an issue that restrains engineering applications of ionic electroactive polymers (EAP). The application of a high impulse voltage has been proposed to accelerate the deformation of water based ionic polymer-metal composites (IPMC). In this paper, focused on ionic liquid (IL) based ionic EAPs, ionic polymer carbon composites (IPCC), IL–IPMC, ionic and capacitive laminates, and bucky gel actuators were selected to verify the effectiveness of the high impulse voltage method. All four were able to be accelerated more than tenfold under high impulse voltages. To investigate the limitations of the high impulse voltage method, constant pulse width measurements were performed on IPCC and IL–IPMC. The deformation speed was almost linear with the pulse amplitude before it reached the maximum deformation. On setting a constant pulse width, a large deformation and a higher speed could be obtained by increasing the pulse amplitude. Additionally, by fixing the pulse amplitude, extending the pulse width induced a larger deformation at a certain speed. Finally, the consumption power and heat issues were investigated via cycling tests. A shorter cycle time (higher frequency) and a higher pulse amplitude led to larger power consumption and higher temperature. The ionic EAPs damaged at high temperature (usually over 100 °C), which is probably due to the positive feedback between Joule heating and ion mobility. In addition to the pulse width, the pulse frequency and amplitude require carefully control when using a high impulse voltage.