Influences of Wire Diameters on Output Power in Electromagnetic Energy Harvester

In this paper, we systematically investigate how the wire diameter affects the output performance of electromagnetic energy harvesters. The harvesters with the same structure but different coils mainly comprised of a magnet array, two coil arrays, a pair of springs and a housing. Different discrete wire diameters of coils are selected to compare the output performance and explore the optimal value. We first set up the theoretical model of the configuration to predict optimal wire diameter and conduct simulations to observe open-circuit voltage and output power, and find the hypothetically optimal diameter leading to the best performance. Subsequently, we fabricate a series of prototypes and conduct four groups of experiments from the following aspects for comparison purposes: constant frequency excitation, frequency sweep, impedance matching and charging capacitors, and validate the theoretically estimated value. When we operate the prototypes under the excitation of 20 Hz, 1.0 g, the maximum average power of 37.45 mW is generated with the best wire diameter, at least 1.62 times as high as that in other cases. The results of capacitor charging experiments, i.e., charging rate, further validate the output power trend. This study can be of great significance for power density improvement in electromagnetic energy harvesters.

Automated summary

In this paper, the authors systematically investigate the effects of wire diameter on the output performance of electromagnetic energy harvesters. Through theoretical modeling, simulations, and experiments, they find the optimal wire diameter that leads to the best performance. The study is of great significance for improving power density in electromagnetic energy harvesters.