Thin Film Dual Probe Heat Pulse (DPHP) Micro Heater Network for Soil Moisture Content Estimation in Smart Agriculture

We report a thin film Dual Probe Heat Pulse (DPHP) micro heater network for long-term data collection of soil moisture. Microheaters nodes were deployed over a large agricultural area and the entire infrastructure was monitored with high spatial and temporal resolution. FTO and ITO coated microheaters were built on a glass substrate. Sensor nodes were powered by a single 5V DC, supported by a central Atmega328 microcontroller for bidirectional communication as well as a database connection. Our network can be extended to monitoring other soil parameters like soil nutrient or pH. The maximum temperature recorded for FTO and ITO heaters for sensor nodes were 71.85°C and 45.45°C respectively while the maximum change of temperature(ΔTM) were 39.12°C and 13.19°C. Thermal cycling experiments were performed to compare the efficiency of the heaters.