Optimization of piezoelectric device with both mechanical and electrical properties for power supply of road sensors

Collecting and converting renewable energy from the road environment relieves pressure on energy supply for road-based sensing and monitoring, and simplify the process of road grid installation. Aiming at the characteristic of mechanical vibration energy collection, the internal structure of the piezoelectric device is optimized. The dowel bar structure is optimized by comparing the output power and stress distribution characteristics, while the actuation mode is selected based on the measured electrical output level and output stability. Then, based on the limit distance of single and dynamic loading, the range of actuation distance under different conditions is clarified. Finally, the electrical performance and application of energy harvester with optimized internal structure are systematically evaluated. The results indicate that the force-electric properties of the energy harvester are superior under the action of the cylinder, the actuation mode of the energy harvester driven by the dowel bar is conducive to improving the electrical performance. The upper limit of actuation distance under high traffic conditions is 1.3 mm. Under long-term high-frequency condition, the power density of the energy harvester can reach 14,726.67 W/m3, and the voltage has almost no attenuation after 100,000 continuous loads. The proposed internal structure improves the electrical performance and durability of the energy harvester, which is conducive to the development of self-powered energy supply for road sensing technology.