The current study examines the feasibility of placing a piezoelectric membrane or "eel" in the wake of a bluff body and using the von Karman vortex street forming: behind the bluff body to induce oscillations in the membrane. The oscillations result in a capacitive buildup in the membrane that provides a voltage source that can be used, far example, to trickle-charge a battery in a remote location. The aim of the hydrodynamic testing is to maximize the strain energy and mechanical power by coupling the unsteady flow field with the vibration of the membrane. The requirement of optimal coupling is best defined as a resonance condition where the membrane has a negligible damping effect on the original von Karman vortex street. (C) 2001 Academic Press.