Optimizing energy harvesting parameters using response surface methodology

Energy harvesting is a process in which energy that would otherwise be wasted is stored and then used to power a system. Due to their unique properties piezoelectric materials are ideal for energy harvesting applications. In this study a pre-stressed piezoelectric composite was pressure loaded dynamically to harvest energy. The objective of this study was to optimize, using piezoelectric diaphragms, relevant parameters that have an effect on the energy harvesting process. Parameters considered were temperature, pressure, resistance and frequency. Response surface methodology was used to develop models to identify optimal parameter ranges and also to predict power conversion capabilities for specific parameter levels. Power densities of approximately 24.27 muW/mm³ were measured at optimal conditions. The model identified an optimal temperature of 12degC and a pressure of 240 kPa, which are in agreement with experimental results.