Abstract
The energy delivery from piezoelectric harvester to resistive load is investigated in this paper. Two types of piezoelectric harvesters are studied, i.e., 33-mode multilayer piezoelectric stack, and the same stack with force amplification frame. Theoretical modeling of generated voltage, electrical power, and power delivery ratio from piezoelectric harvester to resistive load is established. Experiment verification of the theoretical modeling is also carried out. A precise force controllable piezoelectric harvesting measurement method with 1 nm resolution of displacement monitoring was developed to make the experimental results more accurate. Experiment results match well with theoretical modeling, including (1) the voltage cross various resistors, (2) the electrical power delivered to those resistors, and (3) the ratios of the electrical power delivered to resistive loads over the generated electrical power. Moreover, it is proven that 70% of generated electrical power can be directly delivered to a matched resistive load for a real material based piezoelectric energy harvester and √2/2% of generated electrical power can be directly delivered to a matching resistive load for ideal material based piezoelectric energy harvester.
