Energy harvesting using ionic electro-active polymer thin films with Ag-based electrodes

Abstract

In this paper we employ the phenomenon of bending deformation induced transport of cations via the polymer chains in the thickness direction of an electro-active polymer (EAP)-metal composite thin film for mechanical energy harvesting. While EAPs have been applied in the past in actuators and artificial muscles, promising applications of such materials in hydrodynamic and vibratory energy harvesting are reported in this paper. For this, functionalization of EAPs with metal electrodes is the key factor in improving the energy harvesting efficiency. Unlike Pt-based electrodes, Ag-based electrodes have been deposited on an EAP membrane made of Nafion. The developed ionic metal polymer composite (IPMC) membrane is subjected to a dynamic bending load, hydrodynamically, and evaluated for the voltage generated against an external electrical load. An increase of a few orders of magnitude has been observed in the harvested energy density and power density in air, deionized water and in electrolyte solutions with varying concentrations of sodium chloride (NaCl) as compared to Pt-based IPMC performances reported in the published literature. This will have potential applications in hydrodynamic and residual environmental energy harvesting to power sensors and actuators based on micro-and nano-electro-mechanical systems (MEMS and NEMS) for biomedical, aerospace and oceanic applications.

Energy harvesting from underwater vibration of an annular ionic polymer metal composite

“…For each IPMC geometry, power delivery is maximized for a value of the resistance on the order of 100 X. The optimal harvested power varies in the range 0:001-1 lW per unit amplitude of base excitation, in mm, which is comparable with experimental findings in the literature [4,8,12,13,29]. While the model is successful in qualitatively anticipating the dependence of the power delivery on both R load and a, theoretical predictions underestimate experimental findings.…”

“…While the very first efforts on IPMC-based energy harvesting have focused on in-air vibrations [10,61], underwater energy harvesting has been recently studied by several authors, who have contributed to an improved understanding of the process of energy transduction in these materials [4,8,12,13,18,19,29]. Underwater flexural vibrations of an IPMC undergoing base excitation have been analyzed in [8].…”

“…Underwater flexural vibrations of an IPMC undergoing base excitation have been analyzed in [8]. In [4], a similar scenario has been studied to elucidate on the role of the electrodes' properties. To understand the scalability of this design, energy harvesting from a parallel IPMC array with a common base excitation has been investigated in [12].…”

Theory of microstructured polymer–electrolyte artificial muscles

“…Reverse actuation produces a voltage output orders of magnitude smaller than that applied to generate the same curvature. [6][7][8][9][51][52][53][54][55] Thus, the responses from applied voltage and external forces are essentially decoupled, and the two can be summed together to afford the net deflection.…”

Theory of polymer-electrolyte-composite electroactuator sensors with flat or volume-filling electrodes

“…There is great interest in developing electroactuators for soft robots and touch sensors. [1][2][3][4] Amongst the most promising candidates for which are ionic polymer metal composites (IPMCs) [5][6][7][8][9][10][11][12][13][14][15][16] and composites made from hydrated ionomers with carbonbased electrodes. 3,4,[17][18][19][20][21][22][23][24][25][26] Generally, electroactuators composed of polymer-electrolyte films, such as Nafion (where the proton has been replaced by a mobile bulky cation) [11][12][13][14] confined between two electrodes, curve in response to an applied voltage across the electrodes (forward actuation).…”