Development and performance analysis of hemispherical piezoelectric transducer for road applications

Following the extensive research on piezoelectric technology and the increasing popularity of intelligent transportation during the past few years, the harvesting of pavement vibration energy has attracted increased research attention. At present, most innovations in the direction of the road piezoelectric energy are focused on the materials and structures of the transducers. However, few transducers meet the road requirements. Therefore, in this study, a hemispherical piezoelectric transducer was developed for road applications. We also analyzed the effects of different sizes and structures of transducers on energy harvesting efficiency based on laboratory tests, and the outcomes were compared with those from plane transducers. Under the excitation frequency of 10 Hz and the load of 0.7 MPa, the maximum output power of the planar transducer was 0.422 mW, while the power of the hemispherical transducer at the same load was 0.765 mW. Based on the dynamic load test, the ultimate load of the hemispheric transducer was 1900 N, which was 2.66 times that under standard axial load. Subsequently, a dynamic fatigue test was conducted for 24 h at the excitation conditions of 10 Hz and 0.7 MPa, wherein the voltage attenuation of the plane transducer exceeded 60%, while that of the hemispheric transducer was <20%. The experimental results show that the structure had a stable performance and good durability, and its strength and acquisition efficiency met the requirements of road transducers.