MEMS Graduate Student Seminar: Improving Piezoelectric Energy Harvesting from an Aeroelastic System

Our experimental study sought to answer the question: how to maximize the piezoelectric power extraction of an aeroelastic system? A simple rectangular cantilever plate, which experiences non-linear aeroelastic limit cycle oscillations (LCO), was used as a basic vibrating system. The plate was covered entirely with piezoelectric elements on both sides. This makes it different from previous experiments, which typically utilize a single element at the root. By adding small discrete masses along the plate, we were able to increase the power generation efficiency by 230% while reducing the airspeed required to produce this power, from 22.8 m/sec to 17.4 m/sec, and the level of vibrations from 77 g to 24 g. Moreover, the energy harvester can be exploited over a range of air speeds without structural failure. Our experiments show several results:
¿ With proper mass placement, piezo-elements near the tip of the vibrating plate can generate more power that those near the root.
¿The increased damping of the system contributes to a more efficient and sustainable power generator.
¿For a power generator which is based on an elastic structure which experience large deflections, the use of PVDF piezo-elements is advantageous, as opposed to more efficient ceramic based elements.
Our goal for the results of this work to contribute to a more practical piezoelectric energy harvesting solution based on aeroelastic effects.