Minimally Invasive Micro Needle Sensors for Plant Growth Analysis in Agrivoltaic Fields

A plant's physiology is constantly evolving depending on the environment it grows. The critical environmental factor for a plant is its exposure to sunlight. With the increase in the adoption of renewable energy, vast agricultural lands are subject to the mass deployment of solar panels, due to which plant growth is severely affected by the blockage of sunlight. To monitor the health of these plants and extract key growth factors, we need to develop wearable plant sensors. Our project aims to design and fabricate a micro needle array (MNA) based minimally invasive sensor which can observe minute changes in plant physiology. This MNA sensor should be capable of continuous data acquisition in real-time using electronic sensing of versatile physiological aspects, mainly electrical impedance. The MNA sensor would constitute MNA's serving as electrodes, an AD5933 impedance analyzer chip, an analog frontend circuit, and an Arduino Uno microcontroller unit for data processing. After the MNA sensor is designed and fabricated, we will test it on the agrivoltaic field. Categorization must be done on the acquired data to extract useful information regarding plant growth. Electrical impedance data can provide valuable insights like water content, ion concentration, and fluid movement, which can aid us in finding optimal health conditions for a plant to grow. We will first fabricate a high aspect ratio MNA while ensuring low fabrication cost and successfully implementing RF impedance spectroscopy for improved performance compared to biomass determination. The sensor circuit will help us analyze how nutrients, growth stage, water content, acclimation, and damage related to the impedance measurement. Our MNA sensor will be capable of providing distinguished data for a plant under normal conditions and under agrivoltaic settings. Using the MNA sensor on different plants under different conditions will allow us to find specific plants suited for shaded regions, which can help us utilize the agrivoltaic regions efficiently and effectively.