Wireless Monitoring of Ethylene Gas Using a 3D-Printed Capacitive-Inductive (LC) Sensor

As ethylene gas plays a crucial role in the ripening stages of fruits, monitoring it accurately for food quality and safety purposes is essential. This research aims to utilize a capacitive-inductive (LC) sensor [2] that can be 3d printed to detect ethylene levels in tomato plants. The 3D printing fabrication as an additive manufacturing technique offers design flexibility and customization, faster prototyping, and cost-effectiveness. Wireless radio frequency (RF) measurement is used as it is simple and inexpensive, making it applicable to various agricultural applications. The sensor is coated with a layer of tin oxide (SnO₂) as the active material for gas sensing, where the detection mechanism is based on a chemical reaction between ethylene as a reducing gas and tin oxide as an n-type semiconductor [3]. This reaction changes the material charge carrier concentration, resulting in the LC sensor’s capacitance change that ultimately alters the sensor's resonant frequency [4]. The frequency shifts will be measured using a Vector Network Analyzer (VNA). By analyzing these frequency shifts, the study aims to correlate these shifts to ethylene concentration, providing insights into tomato ripening stages and overall quality. This project enhances ethylene detection technology by providing a practical method and offers real-time monitoring, contributing to better food quality and safety and post-harvest waste reduction.

References

[1] Heidarishahrivar, S., Kim, W.S. (2024). Wireless monitoring of ethylene gas using a 3D-printed capacitive-inductive sensor. in preparation.
[2] Kalhori, A. H., Kim, T., & Kim, W. S. (2023). Enhanced RF response of 3D-printed wireless LC sensors using dielectrics with high permittivity. Flexible and Printed Electronics, 8(1), 015013.
[3] Wang, Y., Yang, L., Dall’Agnese, C., Chen, G., Li, A.-J., & Wang, X.-F. (2020a). Spray-coated Sno2 electron transport layer with high uniformity for planar perovskite solar cells. Frontiers of Chemical Science and Engineering, 15(1), 180–186.
[4] Agarwal, M., Balachandran, M. D., Shrestha, S., & Varahramyan, K. (2012). SnO₂ nanoparticle based passive capacitive sensor for ethylene detection. Journal of Nanomaterials, 2012(1).