Rotating-Disk-Based Hybridized Electromagnetic–Triboelectric Nanogenerator for Sustainably Powering Wireless Traffic Volume Sensors

TLDR

Wireless traffic volume detectors are essential for real‑time traffic‑flow measurement, but their battery dependence makes maintenance difficult, especially in remote or widely distributed locations. This work seeks to create a self‑powered wireless traffic volume sensor that eliminates battery replacement. The sensor uses a rotating‑disk hybrid of triboelectric and electromagnetic generators to harvest energy from vehicle‑generated wind. At 1000 rpm, the hybrid generator delivers 17.5 mW (55.7 W m⁻³) at 700 Ω, enough to activate a wireless transmitter for real‑time tunnel traffic monitoring, illustrating the viability of triboelectric nanogenerators for sustainable traffic sensing.

Abstract

Wireless traffic volume detectors play a critical role for measuring the traffic-flow in a real-time for current Intelligent Traffic System. However, as a battery-operated electronic device, regularly replacing battery remains a great challenge, especially in the remote area and wide distribution. Here, we report a self-powered active wireless traffic volume sensor by using a rotating-disk-based hybridized nanogenerator of triboelectric nanogenerator and electromagnetic generator as the sustainable power source. Operated at a rotating rate of 1000 rpm, the device delivered an output power of 17.5 mW, corresponding to a volume power density of 55.7 W/m(3) (Pd = P/V, see Supporting Information for detailed calculation) at a loading resistance of 700 Ω. The hybridized nanogenerator was demonstrated to effectively harvest energy from wind generated by a moving vehicle through the tunnel. And the delivered power is capable of triggering a counter via a wireless transmitter for real-time monitoring the traffic volume in the tunnel. This study further expands the applications of triboelectric nanogenerators for high-performance ambient mechanical energy harvesting and as sustainable power sources for driving wireless traffic volume sensors.