Toward Self-Powered Sensors for Traffic Monitoring and Energy Harvesting—Fundamental Principles and Results Based on SbSI/Epoxy Resin Nanocomposite

In this article, the application of nanosensors based on epoxy resin and antimony sulphoiodide nanocomposite for traffic monitoring is presented for the first time. The physical principles of the traffic measurements via the piezoelectric effect have been explained. The excitation mechanism of the piezoelectric charges in a nanocomposite by a moving vehicle is also discussed. This article demonstrates the sensor’s capability for speed measurement and investigates the influence of vehicle speed on the sensor output voltage and generated energy. It is emphasized that speed measurement should be based on the time interval between voltage peaks generated by vehicle wheels rather than voltage amplitude. The peak-to-peak voltage, energy density, as well as instantaneous and average power densities from the unit volume of the nanocomposite generated per unit of vehicle load moving at a unit speed are calculated. This article also outlines future directions for the development of these sensors, intending to enhance energy harvesting efficiency.