Energy harvesting from a fiber-constrained dielectric elastomer generator embedded into a novel floating wave energy harvester

With the increasing energy demand and growing concern about greenhouse gases emissions from fossil fuel combustion, converting the ocean wave energy into the electrical energy has emerged as a promising and sustainable solution. This paper proposes a novel floating ocean wave energy harvester based on the fiber-constrained dielectric elastomer generator (DEG) arrays and investigates the energy harvesting (EH) performance of the fiber-constrained DEG embedded into the harvester. A theoretical analysis model of the fiber-constrained DEG describing the free relaxation process is developed and verified by the existing experimental data. On this basis, the electrical energy and conversion efficiency of the fiber-constrained DEG are comprehensively analyzed under diverse system parameters, aiming to explore the feasible methods for performance improvement. Results show that both the electrical energy and conversion efficiency are enhanced by shortening the cycle period, boosting the output voltage, and increasing the time ratio of the rising segment in a cycle period. Variations of the electrical energy and conversion efficiency with the input voltage exhibit the non-monotonic behavior. In addition, at low input voltage, enlarging the maximum stretch ratio improves the EH performance, while at high input voltage, the overlarge maximum stretch ratio goes against the performance improvement. The average output power of the harvester with different lengths of rods in its displacement magnifying mechanism is also investigated. Results show increasing the rod length can improve the average output power. In addition, results can help to provide a guidance for designing a high-performance DE-based floating wave energy harvester.