Effects of the electrode interface on the electric properties of IPMC for artificial muscles

Abstract

Artificial muscle has been interested in the applications such as a man-made material or device performing a substitution function of biological muscles. The biomimetic artificial muscle indicates an actuator system controlled by the electric signal of nerve-muscle system. Ionic Polymer-Metal Composites among various Electro-active polymers, which is simple and easy to design and fabricate and driven under relatively low voltage, and has similar nature with human muscles in force and displacement, has been studied intensively to apply for biomimetic applications in the fields of artificial muscles, robot, space and MEMS. The principle of IPMC actuation under electric field is supposed to be the ion cluster flux and electro-osmotic drag of the water from the anode to cathode direction through the hydrophilic channels in the polymer chains. This coupled electrical-chemical-mechanical response of IPMCs depends on the structure of the backbone ionic polymer, the morphology and conductivity of the metal electrodes, the nature of the cations, and the level of hydration. The response of IPMC may be controlled by many factors, such as the intrinsic properties of its components, the dimensions of the device, and the electrode-forming process. We intended to modify the interfacial characteristics between electrode and membrane to enhance deformation responses, by obtaining platinum deposits accumulated by different time and concentration of membrane soaking in platinum solution in ion-exchange progress. It was found out that our IPMCs show the enhanced performance in the electrical properties as well as actuation behaviors.