Mechanical model and analysis of ionic polymer metal composites biomimetic actuators

Employing composite beam theory, mechanical model for IPMC (ionic polymer-metal composite) actuator is described in this paper. Material’s stiffness is the main governing parameter for bending behavior. Firstly, tensile elastic modulus and bending elastic modulus of composite beam are deduced analytically. FEA is a useful method for predicting the force-displacement relationship of an IPMC actuator, which is key data to effectively design many engineering devices of interest. For a cantilever IPMC actuator, tip displacement was simulated by finite element analysis (FEA) according to the loading data of measured force under an input voltage. With the linear static analysis, employing the solid model and force couples loading, the actuation displacements of a cantilever IPMC actuator were simulated to show an excellent agreement between the simulated tip displacements and experimental results. The modulus of IPMC actuators was also estimated from the simulation of tip displacement. The estimation is much more accurate than analytical solutions. Indicated by the results from the FEA agreeing with the measured data from experiments, the analysis method can be adopted for modeling of IPMC actuators with advanced shapes and other boundary conditions.