Vibration energy harvesting with stretchable electrets

Abstract

Motivated by the demand for self-powered portable wearable electronics systems and self-actuated wireless sensors, the development of the energy harvesters that can convert ambient energy into electricity is of great interest. In this study, we fabricated energy harvesters based on stretchable wave-shaped fluorinated ethylene propylene (FEP) electret films using a predesigned bi-stable structure. The energy harvesting performance of the devices with a length of 30 mm and a width of 10 mm was investigated in a stretching mode at various exciting frequencies, load resistances, seismic masses and surface potentials of FEP electrets films. Using $12.5~\mu m$ thick wavy FEP electrets with a surface potential of −500 u and a seismic mass of 3 g cemented on the center of the harvester, the generated power across the optimal load resistance amounts to $355~\mu W$ at 22 Hz for an input acceleration of 1 g. (g is the gravity of the earth).