Fluid interaction of segmented ionic polymer-metal composites under water

The numerous possible applications of the Ionic Polymer-Metal Composite (IPMC) as an underwater propulsor have lead to the investigation of the IPMC behavior in an aqueous environment. This study compares the performance of the IPMC when subjected to fluid drag forces to its performance without such forces. Both the form (i.e. pressure) drag and the viscous (i.e. skin friction) drag forces experienced by the IPMC due to the surrounding liquid are modeled. These forces are incorporated into an existing analytical model of a segmented IPMC1, which adequately models the relaxation behavior of the IPMC. It is important to note that it is assumed that the IPMC exhibits planar motion, i.e. the center of mass does not move in the direction normal to the plane of the bending motion, therefore the hydrodynamic model developed is 2-dimensional. The maximum IPMC deflection and amount of relaxation predicted for aqueous and non-aqueous environments are compared. Results from this model are used to assess the suitability of the IPMC for underwater use.