An internal resonance based frequency up-converting energy harvester

Frequency up-converting vibration energy harvester can bridge the gap between high-frequency response and low-frequency input, greatly increasing the efficiency of energy conversion. This article proposed a novel frequency up-converting energy harvester based on 1:3 internal resonance in 2 degree-of-freedom cubic nonlinear systems. The harvester consists of two asymmetric cantilevers corresponding to two vibration degrees-of-freedom. The ratio of cantilevers’ first-order resonances is (or close to) 1:3. When excited frequency matches the resonant frequency of the first assisting cantilever, 1:3 internal resonance of the harvester system occurs, leading to drastic vibration of the second generating cantilever at its resonance. The generated voltage frequency is then three times increased. Finally, simulated and experimental results clearly proved this frequency up-converting principle. In addition, the resonant frequency tuning and wideband behaviors of the harvester were also investigated, which increased the viability of the proposed harvester under the practical environment vibrations.