Analysis of vibration energy harvester with 2D metamaterial structure

In this paper, we propose a vibration energy harvester with high power generation efficiency in low-frequency band. The target frequency is below 10 Hz, which is a frequency band caused by human motion. Metamaterial structure has high flexibility even in thick film. So, the metamaterial structure of the elastic layer effectively reduces the rigidity of the device, and it can be expected to low resonance frequency and increase the amount of deformation. The proposed device is a cantilever type and it has a metamaterial structure in the elastic layer. As a result of the FEM analysis, the metamaterial type indicated a low resonance frequency of 8 Hz which is 36% of the flat plate type. In addition, the electric power generation at the primary resonance is 0.9 μW, which is three times that of the flat plate. The proposed harvester indicated the possibility to achieve high electric power generation and low resonance frequency, simultaneously.