Live Demo of a Transient-Motion-Powered Human Motion Detector

The development of Internet of Things (IoT) has placed a strong demand on human motion detection technologies. Motion detectors acts an essential role in many civil applications, such as home security, occupancy and activity monitoring, retail analysis, etc. Emerging energy harvesting technologies provide promising solutions towards the ubiquitous and everlasting deployments of motion detectors. However, most existing battery-free solutions require special environmental conditions and suffer from frequent energy outages. Therefore, their applications are still very limited. This live demonstration exhibits a transient-motion-powered motion detector, named ViPSN-E, where "ViPSN" stands for vibration-powered sensor node [1]; "E" stands for an energy-mode device. ViPSN-E can carry out maintenance-free motion detection and wireless communication by making good use of the energy harvested from an instantaneous motion. The prototype of ViPSN-E is shown in Fig. 1. The system is developed based on ViPSN [1], an open-source development platform specified for vibration- powered IoT devices. ViPSN-E is composed of four parts: a piezo-magneto-elastic structure as energy harvester, a self- powered synchronized switch harvesting on inductor (SP- SSHI) interface circuit [2], an enhanced energy management unit, and a Bluetooth low energy (BLE) unit. The piezo- magneto-elastic harvester is composed of a low-cost piezoelectric cantilever and a pair of magnets, which are used to induce a plucking excitation in a transient and one-way movement.