Preliminary Steps Towards a Low Power Integrated Circuit for AgriTech: a Relaxation Oscillator for Stem Impedance Monitoring

The main challenges in modern agriculture involve addressing the disruptive environmental effects caused by crop and livestock production, which are essential for human survival. Emerging trends point towards a world of pervasive IoT (Internet of Things) nodes, where low-cost, low-power, and in-vivo plant sensors can detect abiotic and biotic stresses at the earliest stages. This paper presents a preliminary study of an integrable, low-power relaxation oscillator, consisting of a Schmitt trigger in a feedback loop with the plant’s stem to evaluate its health status. Simulations have been conducted to compare the energy consumption of this circuit with state-of-the-art electronic sensors, focusing on energy usage per measurement. The results indicate that this new solution can sense the plant’s health status with an energy consumption below 10 µJ per measurement, which is at least an order of magnitude lower than existing electronic systems found in the literature.