Study on effects of the damping ratio on output performance of micro electromagnetic vibration energy harvesters

The damping ratio plays an important role in the energy acquisition and energy conversion of micro vibration energy harvester. The paper focused on damping effects of electromagnetic vibration energy harvesters and discussed the effects of the electrical damping/mechanical damping on the output performance of micro electromagnetic vibration energy harvesters. In our experiments, the damping effects on the output voltage, resonant frequency, power and efficiency of the vibration energy harvester were investigated. Both experiments and theoretical analysis suggest that the amplitude of output voltage increases firstly with electrical damping and then decreases slowly. Moreover, the increasing mechanical damping can reduce the efficiency of micro vibration energy harvesters.