A Self-Powering Wireless Environment Monitoring System Using Soil Energy

• Published in: IEEE sensors journal Vol. 15; no. 7; pp. 3751 - 3758
• Main Authors: Lin, Fu-To, Kuo, Yu-Chun, Hsieh, Jen-Chien, Tsai, Hsi-Yuan, Liao, Yu-Te, Lee, Huang-Chen
• Format: Journal Article
• Language: English
• Published: IEEE 01.07.2015
• Subjects: Electrodes; humidity sensor; integrated circuit; Power generation; renewable energy; Soil; Soil energy; temperature sensor; Temperature sensors; Wireless communication; wireless sensor; Wireless sensor networks; renewable energy; humidity sensor; wireless sensor; integrated circuit; Soil energy; temperature sensor
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2015.2398845

This paper presents a self-powering wireless environment monitoring system using renewable and cost-efficient soil energy. The D-size (55.8 cm 3 ) soil energy cell with carbon and zinc electrodes can produce ~60-100 μW, depending on the water contents and microbial reactions in the soil. The RC circuit model of a soil cell is proposed for understanding the electrical characteristics of the cell. The wireless sensing system, including temperature and air moisture sensors, a custom low-power capacitive sensor readout silicon chip, a microcontroller, and a Bluetooth low-energy transmitter, is demonstrated for long-term environmental monitoring solely by the fabricated D-size soil cell. The capacitive sensor readout chip is fabricated in a 0.18-μm CMOS process and only consumes 3 μW. The capacitance readout range is 160-200 pF. The total power consumption of the wireless temperature and air moisture monitoring system is ~20 μW and 1 mW in the sleep mode and the active wireless data communication operations, respectively. The new technology can enable remote field environment monitoring with less labor-intensive work and battery replacement.