Towards a self-sustained moisture and temperature monitoring system using soil energy

Limited energy source dominates the use of sensor system, especially for outdoor environment monitoring. This paper presents a self-sustained moisture and temperature monitoring system using soil energy. The fabricated 36.5 cm³ soil cell (Zinc-Carbon electrodes) can provide maximum output power of 70μW at a load of 2kΩ. The proposed sensor system includes custom DC-DC converter IC, microcontroller, micro-LCD display and temperature as well as moisture sensors. The system was demonstrated measuring temperature and moisture changes directly using inexpensive and renewable soil energy without external power supply. This technology may enable remote field environment monitoring with less labor-intensive work and battery replacement.