This invention presents a graphene oxide-based sensor probe designed to measure soil moisture at multiple depths accurately. Unlike traditional bulky or surface-limited devices, this probe uses microsensors built into a thin, capacitive design, enabling non-invasive and in-depth analysis of soil water levels. The array sensor consists of interdigitated electrodes coated with graphene oxide, which responds sensitively to changing moisture conditions. With its compact design and use of affordable materials, the probe avoids disturbing the soil matrix and provides real-time, scalable monitoring up to 20 cm depth. The design is suitable for both lab and field applications, offering farmers a low-cost, eco-friendly tool for precision irrigation.
Figure 1. GO-ASP deployed in the soil sample
Efficient irrigation is critical for healthy crop production, especially in regions with limited water availability. Existing soil moisture measurement techniques, such as Time Domain Reflectometry or Frequency Domain Reflectometry, are expensive, bulky, and mainly surface-focused. They often disturb the soil structure, making them unsuitable for in-depth and non-invasive monitoring. Therefore, a low-cost, compact, and accurate solution is needed to monitor soil moisture across different depths without harming the soil matrix.
- Capacitive Sensing Using Graphene Oxide: The sensor uses a graphene oxide (GO) film on interdigitated electrodes (IDE) to detect changes in soil moisture through capacitive sensing.
- Depth-Based Moisture Profiling: It features a thin, flexible probe with multiple vertically aligned microsensors, allowing moisture measurement at various depths up to 20 cm.
- Protective Sensor Housing: Each sensor is sealed with a 3D-printed cover and layered mesh that permits moisture entry while preventing soil particle intrusion.
- High Measurement Accuracy: The system offers an accuracy of ±2.4% when compared with standard oven-drying methods for soil moisture testing.
- Fast and Broad Moisture Response: It is responsive across a wide soil moisture range (3.2%–55.5%) with response and recovery times of 140 seconds and 20 seconds, respectively.
- Optimized for Agricultural Use: The device is lightweight, low-cost, and energy-efficient, making it ideal for large-scale deployment in agricultural fields.
The sensor array measures 22 × 4 × 0.5 cm and includes five GO-coated IDE microsensors, each with eight pairs of 50 μm thick, 90 μm spaced comb-like fingers. Fabricated using metal sputtering, UV lithography, and GO drop-casting, the sensors are housed in a durable 3D-printed ABS casing. The system was tested with black soil and validated against gravimetric moisture methods. Integrated with an Agilent LCR meter (1 V, 500 Hz), it showed strong performance in field tests, including infiltration and uneven moisture distribution studies.
The device is fully developed and tested in lab settings. It has demonstrated reliable soil moisture readings across varying depths and soil conditions and is ready for deployment and scale-up in real-world agricultural environments.
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This invention offers a scalable, eco-friendly, and affordable solution for farmers to optimize irrigation. By enabling precise, in-depth soil moisture tracking, it reduces water waste, supports better crop yields, and contributes to sustainable agriculture practices—especially in water-stressed regions.
- Agricultural soil monitoring
- Environmental sensing
- Smart farming platforms
Geography of IP
Type of IP
201921043074
543246