Assessment of energy harvesting and signal transmission in traffic markings with embedded piezoelectric film transducers

In the establishment of intelligent transportation systems, traffic markings, often serving as surface guidance signs on roads, are facing an urgent need for functional attribute upgrades and innovation. Hence, this study involved embedded piezoelectric film transducers (PFTs) into traffic markings to endow them with the capabilities of energy harvesting and signal transmission. A layered preparation method for protecting the PFTs and optimizing burial depth was developed and validated. The effects of load levels, vibration frequencies, and burial depths on the open-circuit voltage and current responses were systematically investigated. Long-term vibration and high-temperature exposure were applied to the traffic markings with embedded piezoelectric thin film transducers. The results indicated that the layered preparation method effectively protected the piezoelectric film and controlled burial depth. The vibration frequency was directly proportional to the electrical response, while the burial depth was inversely proportional to the electrical response. The maximum voltage reached 9.2 V and the power attained 8.6 mW under lab-based rolling mode. And the maximum voltage reached 6.4 V under lab-based vibration mode. The open-circuit voltage doubled after prolonged vibration of 5 million cycles. A high temperature of 60°C resulted in a 30% reduction in open-circuit voltage.