Researchers in China have developed “smart floor tiles” that track pedestrian traffic without using batteries or cameras, a big step for low-cost, privacy-respecting crowd monitoring and Internet of Things (IoT) applications, tells IEEE Spectrum. The tiles are powered exclusively by the mechanical energy generated when people step on them, using embedded quasi-static toggling (QST) electromagnetic harvesters that convert footstep movement into the electricity needed for sensing and data transmission. This innovation could make crowd counting and direction monitoring more practical in public spaces, transportation hubs, and other environments where understanding foot traffic matters.
Each tile is about 15 millimeters thick and uses the sequence of heel, ball, and toe impacts to determine the direction of movement as well as count steps. Timestamped footstep data are sent via Bluetooth Low Energy to a nearby receiver for processing and real-time analysis. In controlled tests, individual tiles detected movement direction with about 97% accuracy at normal walking speeds and roughly 93% accuracy even during running. Similar performance, around 95% accuracy, held up during multi-day monitoring at a lab entrance, demonstrating the system’s robustness outside laboratory conditions.
One clear advantage of this tile-based approach is that it sidesteps privacy concerns associated with camera systems, which can record identifiable images of people in public areas. These tiles instead measure footsteps and transmit abstract data outputs, allowing crowd size and movement patterns to be assessed without capturing personal visuals. They are also self-powered and low-cost, which could make deployment scalable across large venues or city networks without expensive infrastructure or frequent maintenance.
Current limitations include a restricted Bluetooth range of about 10 meters and reduced accuracy when people walk side-by-side rather than in a single file. The research team has formed a startup, ViPSN Ltd., to commercialize the technology and explore additional uses, such as security monitoring and virtual reality applications, broadening the potential impact of this novel IoT sensing platform.