Derivation of Transfer Function of an IPMC Actuator Based on Pseudo-Rigid Body Model

In this article an effort has been made to derive the transfer function of an ionic polymer metal composite (IPMC) actuator. The transfer function obtained is based on the experimental deflection data and following the pseudo-rigid modeling technique. Initially an experiment is conducted with an IPMC actuator to measure its bending characteristics with input voltages. Subsequently expression for bending moment with radius of curvature is established. IPMC has been modeled then following the pseudo-rigid body modeling technique as fix-pin support type of cantilever mode with end-moment loading and its derivation is explained in detail. Based on the experimentally obtained bending moment, IPMC has been modeled to obtain the distributed force, spring constants, characteristic radius factor, and pseudo-rigid body angles. Energy based dynamic model of the IPMC actuator has been formulated following the Lagrangian principle based on the tip position in 2D. Transfer function is then obtained with respect to pseudo-rigid body angle and input voltage. Simulations have been performed to demonstrate the system response.