Wide bandwidth nonlinear 2-DOF energy harvester: Modeling and parameters selection

Harvesting energy from mechanical vibrations to provide power in remote areas where there is no lines of electricity has attracted a great research interest. Linear vibration energy harvesters (VEH) are not able to scavenge energy over broadband of frequencies. The performance of the linear harvesters can be improved using the concept of nonlinearity using magnets which has been extensively studied. In this paper, a 2-DOF nonlinear VEH that can maximize the harvested ambient energy over a wide bandwidth is proposed. In order to achieve those requirements, the design of the proposed VEH is based on; first, the cut-out structure of the 2-DOF system that can provide two resonances with significantly high amplitudes; second, parameters selection based on satisfying the dynamic vibration absorber condition that can avoid the anti-resonance between the two peaks while maximizing the response in between those two peaks; third, proper selection of the distance between the two magnets to widen the bandwidth through adding the nonlinearity to the system. Simulations for the proposed harvester are carried out using MATLAB/Simulink over a wide bandwidth of frequencies. The results show that the proposed harvester can generate adequate voltage of 5 volts across a load of 1 GΩ over a wide range of frequency from 26 to 35 Hz for the proper distance between the two magnets that is based on the system parameters. Also, another frequency range from 5 to 11 Hz is targeted to insure that the proposed design methodology can be generalized.