Design and Fabrication of a Novel Electronic Sensor for Detecting Spoilage in Milk

Document Type : Research Article

Authors

1 Department of Electrical Engineering, Kermanshah University of Technology, Kermanshah

2 Department of Electrical Engineering, Kermanshah University of Technology,

3 Department of Mechanical Engineering and Artificial Intelligence Research Center, Ajman University, Ajman, United Arab Emirates

Abstract

Evaluating the quality and safety of milk, a vital component of human nutrition, is of paramount importance. Traditional methods for assessing milk quality, primarily based on chemical tests, are reliable but suffer from high costs, time-consuming processes, and the need for sample destruction. In contrast, microwave sensing technology, particularly using microstrip sensors, offers a novel, cost-effective, non-destructive, and real-time approach. These sensors detect quality changes, including spoilage, by analyzing frequency response variations driven by the material's dielectric properties. This study aimed to design, fabricate, and evaluate a novel microstrip sensor for detecting milk spoilage trends using microwave signals. A microstrip sensor with two passband regions was designed in ADS software and fabricated. Ten commercial milk samples, prepared under identical conditions, were collected over ten consecutive days and stored at a controlled temperature (21°C). The scattering parameter (S21) for each 180 ml sample was measured using a vector network analyzer (VNA). Results showed significant S21 changes in the first passband (1807–2466 MHz) as samples aged. The highest sensitivity was observed at 2166 MHz, with a 7.02 dB amplitude difference between the freshest and most spoiled samples, approximately 105 times the standard deviation (0.067 dB), indicating high resolution and statistical significance. Other frequencies, such as 1807 MHz, showed similar reliable trends. The proposed microstrip sensor is an efficient, accurate, and rapid tool for non-destructive, real-time milk spoilage monitoring, serving as a viable alternative to costly and time-consuming laboratory methods in the food industry.

Graphical Abstract

Design and Fabrication of a Novel Electronic Sensor for Detecting Spoilage in Milk

Highlights

  • The designed microstrip sensor detects milk spoilage non-destructively and in real-time with high accuracy.
  • The sensor’s highest sensitivity was at 2166 MHz, with a 7.02 dB amplitude difference.
  • The amplitude difference was 105 times the standard deviation, indicating high result resolution.
  • This method offers a cost-effective, rapid alternative to traditional laboratory techniques in the food industry.

Keywords

Main Subjects


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Volume 12, Issue 4
July 2025
Pages 353-372
  • Receive Date: 11 June 2025
  • Revise Date: 23 July 2025
  • Accept Date: 28 July 2025
  • First Publish Date: 28 July 2025
  • Publish Date: 23 July 2025