Recent Developments About IPMCs (Ionic Polymer-Metal) Composites: A Review of Performances for Different Conditions

It is of great significance for the production of micro robots and new sensors to develop actuators with "muscle" properties. As a kind of electroactive polymers (EAPs), IPMC (ionic polymer-metal composite) can exhibit significant deformation for very low electrical excitation. These composites, known as the "artificial muscle", can be regarded as intelligent bionic materials. With regard to the mechanism of deformation of IPMC, a large number of experimental studies have proved that the variety of electrodes and water contents relating to IPMC have great influence on its electro-mechanical and mechanical properties. Recent research results about IPMC were summarized here to provide a reference for the design and manufacture of these materials. Our conclusions show that, among the main electrode material, though Pt and Au show excellent stability and conductivity, the utilization is limited due to high cost. While Ag, as electrode material, has better application prospect, due to good conductivity and tensile properties. But the optimal voltage under electrical excitation need to be considered when used in specific conditions, or it will cause rapid failure of Ag-IPMC. In addition, IPMC displays high sensitivity to the water content, the service life of IPMC can significantly be prolonged by increasing the degree of humidity of the working environment. So the prospect of IPMC is appropriate to be used in underwater robots, as drivers or actuators.