In conclusion,the impact vibration energy harvester achieved
significant improvement of output power and power density
compared with the conventional counter part. The 1.53 mW aver-
age output power and 93.2 mW/cm3 power density provided a
promising energy supply for the implantable and portable systems.
By the frequency up-conversion,the reduced mechanical damping
contributed to the efficiency of the energy transfer as high as 69.6%.
Moreover, the low-frequency impact harvester cannot only
demonstrate a high power density but also be especially suitable
for the implementation with MEMS processes.