Characterization of Piezoelectric Cantilever Beams for use in Roadside Vibration Energy Harvesting

This paper investigates a method of characterizing piezoelectric cantilever beams for applications in roadside energy harvesting. Research to date studies piezoelectric harvesting units embedded in pavement, which has a host of logistical issues. Other previous implementations have focused on adhering piezoelectric elements to a substrate that acts as the beam. This paper focuses on an implementation using only the piezoelectric material as the cantilever beam and an initial investigation into the feasibility of harvesting electricity from a cantilever beam system on the roadside. A Piezoelectric element was tested by clamping it to the vibration table and observing the open-circuit voltage over a frequency range of 1 - 200 Hz at approximately 1 G. The test samples had a prominent but narrow-banded resonance at between 20 - 200 Hz, outputting roughly 2.45 - 6.22V_rms, resulting in between 63.6 - 289 μW. These preliminary results show that with the usage of multiple piezoelectric elements and careful considerations in the choice of harvesting circuitry, a usable amount of energy could be generated for some low power applications.