The Design of a MRE-Based Nonlinear Broadband Energy Harvester

In this article, a conceptual design with its architecture of a broadband, vibration-based, nonlinear energy harvester is reported. Its non-linear behavior and its functionality are presented. Compared to that provided by conventional linear beam type of energy harvesters, this nonlinear harvester can provide widen the resonance frequency ranges. Hence, it can collect more vibration energy generated at various dominant rotational frequencies of a rotary machine. A smart material, called Magneto Rheological Elastomer (MRE), was added to the usual beam structured energy harvester. Since MRE is one of the magnetic smart materials, of which their stiffness can be tuned by precisely controlling the applied magnetic field, the stiffness of the combined piezoelectric beam with MRE becomes adjustable. Because of the adjustable stiffness, the resonance frequency of the new beam type energy harvester can be adaptively changed to match with a particular dominant rotational frequency generated by the monitored machine so that maximum vibration energy can be harvested. Moreover, due to the nonlinearity of the new composite beam structure, the range of resonance frequency range can be widened to make it easier to adapt a slightly varying dominant rotational frequency due to the monitored machine has small speed variation. Besides the presentation of design and its with its architecture in the article, the simulated and experimental results of the new non-linear harvester are also reported here. From the comparison study of the bandwidth and the output power generated by the new nonlinear energy harvester against that generated from conventional harvester, the result shows that new non-linear harvester is functioning superior to that of the conventional harvesters.