New Perspective on Planar Inductive Sensors: Radio-Frequency Refractometry for Highly Sensitive Quantification of...

Area of Science:

• Physics
• Materials Science
• Electrical Engineering

Background:

• Planar coils are sensitive to magnetic and electric properties of nearby materials.
• Quantifying magnetic nanoparticles is crucial for applications in biomedicine, food safety, and environmental monitoring.
• Existing inductive sensors lack the sensitivity or focus solely on magnetic permeability.

Purpose of the Study:

• To demonstrate the use of resonant planar coils as reliable sensors for magnetic nanoparticles.
• To develop a mathematical model for quantifying nanoparticle mass using the coil's self-resonance frequency.
• To establish a low-cost, scalable, and automatable sensing solution.

Main Methods:

• Utilized resonant planar coils as inductive sensors operating at radio frequencies.
• Developed a mathematical model correlating self-resonance frequency with nanoparticle mass.
• Validated the model using 3D electromagnetic simulations and experimental measurements.
• Investigated the dependence of calibration parameters on the refractive index of surrounding materials.

Main Results:

• Successfully detected and quantified magnetic nanoparticles using resonant planar coils.
• The developed mathematical model accurately predicts nanoparticle mass from self-resonance frequency.
• Model calibration depends on refractive index, simplifying sensor characterization.
• The sensor system demonstrated superior sensitivity compared to simple inductive and oscillator-based sensors.

Conclusions:

• Resonant planar coils offer a sensitive and reliable method for magnetic nanoparticle detection and quantification.
• The developed mathematical model provides an accurate and simplified approach for mass determination.
• The technology is scalable for portable, low-cost devices applicable in diverse fields.
• This approach represents a significant advancement over existing inductive sensing technologies.