Flexible piezoelectric micro-generator with interdigitated electrodes for energy harvesting
Résumé
This research work deals with the development of high performance flexible piezoelectric microgenerators, able to harvest low frequency (<10 Hz) mechanical energy from wind flows, for instance. Such hybrid microsystems are made of lead zirconate titanate (PZT) films easily transferred onto an insulating polymeric substrate. In order to optimize the output voltage and harvested power, an interdigitated electrode structure is adopted. By manually subjecting the micro device to a pseudo-sinusoidal excitation of about 2 Hz, an output voltage of 7.7 V and a power of 220 nW are obtained, using a resistive load of 100 MΩ. Owing to the IDE design, the optimum load resistance is found to be about 71 GΩ, yielding calculated huge maximum voltage values (6.2 kV) and power (137 µW). These results make the studied micro-generators promising candidates to electrically power miniature, autonomous wireless electronic micro devices, such as distributed sensor networks.