Investigations on actuation characteristics of IPMC artificial muscle actuator

Electromechanical response characteristics of ion-exchange polymer metal composite (IPMC), known as a material for artificial muscle actuators, varies extremely depending on the driving method. With respect to the power management the driving method is one of the important considerations though it has not been investigated sufficiently up to now. Its efficiency is critical to enhance the performance of an IPMC system, especially self-contained one. The primary objective of this paper is to investigate electromechanical response characteristics of the IPMC actuator according to driving methods. We begin with developing an equivalent electrical circuit model for the IPMC actuator using experimental data. Based on this model, discuss how the waveforms and frequencies of driving inputs have effect on the characteristic features of the IPMC actuator. Typically square, triangular and harmonic waves are applied as the driving waveform of the IPMC actuator. By employing Fourier techniques, the responses of the IPMC actuator on each input waveform are mathematically analyzed. From this study, we conclude that large consumption of current during actuation is caused by the high frequency components of the driving waveforms because the IPMC actuator has the characteristics of damped high pass filter. A desirable method of driving the IPMC actuator is proposed and its validity is experimentally confirmed.