Dielectric elastomer–based energy harvesting: Material, generator design, and optimization

Abstract

Electroactive polymers are soft capacitors made of thin elastic and electrically insulating films coated with compliant electrodes offering a large amount of deformation. They can either be used as actuators by applying an electric charge or used as energy converters based on the electrostatic principle. These unique properties enable the industrial development of highly efficient and environmentally sustainable energy converters, which opens up the possibility to further exploit large renewable and inexhaustible energy sources like wind and water that are widely unused otherwise. Compared to other electroactive polymer materials, polyurethanes have certain advantages over silicones and acrylates. Due to the inherently higher permittivity as well as the higher dielectric breakdown strength, the overall specific energy, a measure for the energy gain, is better by at least factor of 10, that is, more than 10 times the energy can be gained out of the same amount of material. In order to reduce conduction losses on the electrode during charging and discharging, a highly conductive bidirectional stretchable electrode has been developed. Other important material parameters like stiffness and bulk resistivity have been optimized to fit the requirements. We also report on different measures to evaluate and improve electroactive polymer materials for energy harvesting by, for example, reducing the defect occurrence and improving the electrode behavior.

Mechanics of dielectric elastomers: materials, structures, and devices

“…Specific examples of DEs include acrylics, silicones, polyurethanes, fluoroelastomers, and ethylene-propylene rubbers. Key attributes of such materials, including large actuation strain, fast response, light weight, silent operation, and low cost, provide the unique combination for the task of muscle-like actuation and thus gain increasing attention for a diversity of structures, devices, and applications over recent years (O'Halloran et al, 2008;Carpi et al, 2010;Anderson et al, 2012;Sheng et al, 2012;Graf et al, 2014).…”

Design and modeling of an innovative wave energy converter using dielectric electro-active polymers generator

“…(12), the hydrodynamic force is obtained in Eq. (17) (17) F PTO is the PTO force which couples the electromechanical forces of the 1 st and 2 nd DEAP generator. As shown in Fig.…”

“…16 Development a solution for artificially increasing the coupling factor of electrostrictive materials based on the optimizing the frequency of the electric field and the amplitude strain of the mechanical excitation were studied to increase in the generated current. 17 Graf C et al developed a polyurethanes which have certain advantages over silicones and acrylates. 18 The energy gain and other important material parameters had been optimized to fit the requirement for energy converter.…”

Dielectric Elastomers for Energy Harvesting

“…Finally, based on data presented in [43] we include Table 1, which provides the important mechanical and electrical properties of some DEs that can be used for EH. More information about specific DEs appearing in the table, in particular polyurethanes (i.e.…”