Coupling High Resonant Frequency Piezoelectrics to Human-Scale Frequencies for Energy Harvesting

For low-power applications, piezoelectric transducers are often utilized through direct and vibrational excitation. Mechanical energy exists almost everywhere there is movement—vibrations in bridges, wind spinning turbines and human steps onto the floor—and the direct piezoelectric effect inherent in piezoelectric materials converts the mechanical energy into electrical energy. Piezoelectricity can be advantageous in certain applications due to its chemical stability, scalability, and low dependence on environmental conditions, such as temperature and pressure. In this paper we will discuss two distinct excitation methods for energy harvesting optimization. First, a compressive system was simulated and tested, with the goal of simulating human footfall, and the second utilizing a plucking motion, with the goal of coupling high resonant frequencies inherent in piezoelectrics, to low human scale frequencies. The work performed here is in conjunction with NASA for the development of a novel, piezo-driven, interactive flooring system which will be installed at Kennedy Space Center on Cape Canaveral in the summer 2017.