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Ionic polymer-metal composites (IPMCs) are an interesting subset of smart, multi-functional materials that have shown
promises in energy conversion technologies. Being electromechanically coupled, IPMCs can function as dynamic
actuators and sensors, transducers for energy conversion and harvesting, as well as artificial muscles for medical and
industrial applications. Like all natural materials, even IPMCs undergo fatigue under dynamic load conditions. Here, we
investigate the electromechanical fatigue induced in the IPMCs due to the application of cyclic mechanical bending
deformation under hydrodynamic energy harvesting condition. Considering the viscoelastic nature of the IPMC, we
employ an analytical approach to modeling electromechanical fatigue primarily under the cyclic stresses induced in the
membrane. The polymer-metal composite undergoes cyclic softening throughout the fatigue life without attaining a
saturated state of charge migration. However, it results in (1) degradation of electromechanical performance; (2)
nucleation and growth of microscopic cracks in the metal electrodes; (3) delamination of metal electrodes at the
polymer-electrode interface. To understand these processes, we employ a phenomenological approach based on
experimentally measured relaxation properties of the IPMC membrane. Electromechanical performance improves
significantly with self-healing like properties for a certain range of relaxation time. This is due to reorientation of the
backbone polymer chains which eventually leads to a regenerative process with increased charge transport.
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