A multimodal and multidirectional vibrational energy harvester using a double-branched beam

摘要

Vibrational energy harvesters, which are generally based on a single cantilever beam, are mainly effective for excitations perpendicular to the beam. However, typical ambient vibrations are of multifrequency and are multidirectional. To achieve full harvesting of multifrequency vibrational energy in multiple directions, this letter proposes a multidirectional vibrational energy harvester utilizing multimodal vibrations of a double-branched beam that has four natural frequencies below 22 Hz. Comparison experiments in different directions demonstrate an improvement of energy harvesting when this double-branched beam is used. Under horizontal excitation, the maximum open-circuit voltage is increased to 1845%. Under vertical excitation, the average power density is increased over 3800 times. The experimental results indicate that this structural design significantly improves the energy collection efficiency in both horizontal and vertical directions, even with a lighter structural weight. Published by AIP Publishing.