Microfluidic Microwave Sensor Loaded with Star-Slotted Patch for Edible Oil Quality Inspection

Area of Science:

• Electrical Engineering
• Materials Science
• Food Science

Background:

• Edible oil quality degrades with high-temperature exposure, altering its dielectric properties.
• Accurate and non-destructive methods are needed to assess edible oil quality.

Purpose of the Study:

• To develop and present a microfluidic microwave sensor for detecting edible oil quality.
• To correlate changes in dielectric permittivity with oil quality degradation.

Main Methods:

• A microfluidic microwave sensor utilizing a star-slotted patch and a substrate integrated waveguide with a pentagonal slot antenna was designed.
• The sensor operates within the 2.3–2.9 GHz frequency range, centered at 2.68 GHz.
• Edible oil quality was assessed by measuring the resonance frequency offset of the input reflection coefficient, which is influenced by the oil's dielectric permittivity.

Main Results:

• The sensor successfully detected variations in edible oil quality by measuring shifts in resonance frequency.
• The system demonstrated sensitivity to changes in the real part of complex permittivity, ranging from two to three.
• The resonant approach ensured high sensing accuracy for detecting greasy liquids.

Conclusions:

• The developed microfluidic microwave sensor provides an effective method for non-destructively evaluating edible oil quality.
• This sensor technology can be applied to monitor oil degradation and ensure food safety.
• The sensor's ability to detect subtle changes in dielectric properties highlights its potential for real-time quality assessment.