Experimental Investigation of Load Characteristics of Piezofilm-based Energy Harvester

Harnessing and usability of electrical energy from piezofilm-based energy harvester is investigated. Three possible combinations such as parallel, series-parallel and series configurations of piezofilms are investigated for load carrying capability. A total of six mass loaded piezofilms are employed in this study. An artificial vibrator is used to simulate the ambient vibration to generate electrical energy from the piezofilms. A commercial passive converter is used to convert generated ac power into usable dc power. Load characteristics are obtained at different vibrating frequency for all the three configurations. Among these three configurations, experimentally it is found the parallel combination of the piezofilms is the best configuration as far power generation capability is concerned, even at low vibrating frequency. It is also noticed that, the peak power is obtained at almost equal load for the first two configurations while the same is found to be at larger load resistance for the last configuration. The possible reasons for differences in the load characteristics of the three configurations are discussed.