Hybrid polymer/piezoelectric oxide bilayer films for low frequency energy harvesting

In this paper, we present the fabrication of piezoelectric thin film based-vibration energy harvesters with interdigitated electrodes (IDE) on a polymer substrate. The deposition of the lead zirconate titanate thin layers onto aluminium foil and the transfer onto a polymer substrate are realized using sol-gel process and a chemical method, respectively. The characteristics were studied using a bending cantilever structure under controlled oscillations. We show that harvested energy with constant acceleration is inversely proportional to the resonant frequency tuned by adding proof mass to the cantilever. For a proof mass located at 8 cm from the clamped end, a maximum power output of 127 $\mu$W was obtained at 9.9 Hz against a resonance frequency of 16 Hz and a maximum power of 72 $\mu$W with a mass at 4 cm. These results demonstrate the high flexibility and the potentialities of the so-called hybrid polymer/oxide micro-generator for mechanical energy harvesting from wind flow or body motion.