Robust, Long-Term, and Exceptionally Sensitive Microneedle-Based Bioimpedance Sensor for Precision Farming.

Area of Science:

• Agricultural Engineering
• Sensor Technology
• Plant Science

Background:

• Precision farming requires effective, non-disruptive crop monitoring tools.
• Current methods may interfere with plant growth or lack sensitivity.
• Electrical impedance spectroscopy (EIS) offers a promising non-destructive approach.

Purpose of the Study:

• To develop and evaluate novel impedimetric sensors with microneedles (MNs) for in-situ crop monitoring.
• To assess the fabrication method and performance of these microneedle sensors.
• To demonstrate the potential of EIS-based sensors for precision agriculture applications.

Main Methods:

• Fabrication of microneedle (MN) impedimetric sensors using a novel micromolding technique.
• Characterization of MN quality and replication fidelity using scanning electron microscopy.
• Deployment of sensors in open-air settings for crop impedance measurements.
• Validation of sensor performance against conventional planar sensors using Arabidopsis thaliana.

Main Results:

• Microneedle sensors achieved sensitive impedance spectra with low noise (average relative noise: 3.83%).
• The fabrication method demonstrated high fidelity and durability, supporting over 20 replication cycles.
• Impedance measurements correlated with changes in plant lighting and hydration.
• Sensor performance was validated against traditional planar sensors.

Conclusions:

• Novel microneedle impedimetric sensors are effective for non-destructive, open-air crop monitoring.
• The developed fabrication technique ensures high-quality, repeatable sensor production.
• Detected impedance changes linked to environmental factors suggest broad applicability in precision farming for optimizing crop management.