Dielectric elastomers can be used as generators, converting mechanical strain energy into electrical energy using the polymer’s capacitive behavior. The amount of energy gain depends, in addition to the mechanical setup of the device, mainly on the material parameters and the energy harvesting cycle used. While the usefulness of small-scale prototypes for harvesting the energy of waves has already been demonstrated, using the capability of flow energy in rivers, based on electroactive polymers, is still a significant challenge. After introducing the basic working principle of dielectric elastomer generators, the most unique energy harvesting cycles are described, considering electrical and mechanical losses. To harvest the energy of flowing waters, a novel flow energy converter based on a simple and environmentally sustainable mechanical design has been developed, consisting of an elastomeric tube with a closing mechanism on the outlet. The stationary stretch of such a tube is comparably small, but the resonant operation offers large tube deformations. The basic mechanisms of the flow energy converter are modeled, and confirmed on the basis of a FSI simulation, and a control concept is proposed. The expected mechanical behavior of the tube is demonstrated with a small-scale prototype. It can be concluded that a very efficient, resource-saving, scalable and lightweight energy harvesting system can be realized at comparably low frequencies in the infrasonic range.
Transducers based on dielectric electroactive polymers (DEAP) use electrostatic pressure to convert electrical into mechanical energy or vice versa. To scale up the actuation or the energy gain, multilayer transducers like DEAP stack transducers are appropriate. Within this contribution, a model of such a stack transducer is derived and experimentally validated. The model is based on a multi-domain approach to describe the mechanical dynamics and the electrical behavior of the DEAP. Since these two domains influence each other they are coupled afterwards by a novel approach using interchanging power flows. To parametrize this model, tensile and compression tests for different polymer materials were performed under static and transient considerations. The results of these experiments show that the parameters obtained from the tensile test sufficiently describe the compression mode and can therefore be used for the model. Based on this transducer model the overall energy and the different parts of the multi-domain are analytically determined for arbitrary operating points. These expressions for the energies are finally used to optimize well-defined coupling coefficients, by which a maximum part of the electrical input energy is converted to mechanical energy, especially mechanical work.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.