Experimental study on road piezoelectric energy harvesters' power generation performance under erosive environments

Piezoelectric energy harvesters (PEHs) located within the road surface structure are affected by vehicle loads as well as road environments such as rain and salt erosions. However, research on the latter aspect is lacking. In this study, a type of PZT-5H piezoelectric transducer with excellent performance was fabricated and embedded in concrete and asphalt concrete test specimens, and subsequently, the variation laws of output voltage and output power of piezoelectric transducers were examined in an erosive environment. The test results indicate that, at first, the output voltage of piezoelectric transducers in concrete structures decreases rapidly to 20% and then remains stable with age; therefore, the final power generation must be considered as the design index of output power. Under the action of salt erosion, the output voltage of piezoelectric transducers decreases although a sudden increase in voltage was observed. Further, the trend of output voltage was found to change rapidly with the increase in sulphate concentration. The higher the chlorine-salt concentration, the larger the decrease in output voltage. Finally, through comparisons of the piezoelectric transducers in different road surface structures, the open-circuit voltage and maximum output power of the piezoelectric transducers in the asphalt concrete structure were found to be 100 and 10 000 times higher than those of the concrete structure, respectively. In conclusion, the results of this study confirm that the erosive environment affects the power-generation performance of piezoelectric transducers to a certain extent, and thus, these results provide a reference for the future promotion and application of piezoelectric transducers on roads.