Design and Laboratory Validation of a Force-Amplified Piezoelectric Energy Harvesting Unit
Abstract In this paper, an innovative piezoelectric energy harvesting unit (PEHU) for the piezoelectric energy harvesting system (PEHS) from highway traffic is introduced. The proposed PEHU contains a non-linear force amplification mechanism, which substantially increases the electricity output of the PEHU in contrast to the conventional designs with direct loading to the piezoelectric stacks. Quasi-static laboratory tests have been performed to validate the design and the mathematical model. In a quasi-static load cycle of 1333N, a preloaded PEHU prototype is able to generate a voltage of 128V and a potential electric energy of 120mJ with a displacement as small as 2.54mm. The energy density that the PEHS can potentially deliver is estimated to be 8.64J/(m.pass.lane) and is the highest reported in the literature. This level of power generation suggests that the PEHU has a great potential for roadway energy harvesting.