Experimental Investigation of Piezoelectric Energy Harvesters Applied in Concrete Pavement

This paper proposes the application and manufacturing of piezoelectric devices based on pile and arc-bridge transducers to harvest mechanical energy from concrete pavement. Multi-scale experiments are conducted to clarify the influence of electrical connection, load resistance, traffic speed, and loading times on the electrical properties of the harvesters. The reduced-scale test shows that the transducers should be connected to rectifiers before being connected as an array. Moreover, the output power of the arc-bridge transducer with resistance variations is unstable compared with that of the pile transducer. Accelerated pavement testing illustrates that the output power of the half pile array device increases to 1.7 mW with an optimal resistance of 10.0 MΩ; reducing the internal equivalent resistance is a potential way to increase the energy output. The results also show that the load speeds significantly influence the profile of the voltage and have a minor effect on the generated electric energy in the tested conditions. Furthermore, the electrical properties of the piezoelectric device exhibit no statistical degradation after the electrical fatigue test of 100,000 tire loads, indicating a novel electrical fatigue performance. The findings in this paper can further guide the application of such piezoelectric devices in concrete pavement.