Zero-Power Wireless Sensing System Based on Piezoelectric Energy Harvesting Towards Battery-Free IOT Applications

Employing energy harvesting technology to convert ambient energy into electricity in IOT nodes is expected to solve problems caused by battery-powered devices. This paper proposed a zero-power wireless sensing system based on piezoelectric energy harvesting for battery-free IOT applications. The proposed system consists of a piezoelectric cantilever energy harvesting unit, an SP--PSSHI interface circuit and a buck converter forming up the energy management unit (EMU), a BLE SOC together with a MEMS sensor to acquire and transmit the ambient data accomplishing the wireless sensing unit (WSU) and an IOT host APP for data display. Compared to the state of the art, the proposed system is a highly integration of the energy harvester and a single-board EMU and WSU. All units are packaged into a 44×50×30mm case realizing a compact and easy-to-deploy zero-power sensing system. The average power of the energy harvester is 28.9mW, and the output of the EMU is 3.3VDC of 3.63mW. The IoT host APP can successfully receive and display the vibration and temperature data, therefore establishing a zero-power wireless sensing system with a real battery-free power supply and IoT applications.