A Novel Dual Modality Sensor With Sensitivities to Permittivity, Conductivity, and Permeability

TL;DR

This paper introduces a dual modality electromagnetic sensor capable of simultaneously measuring permittivity, conductivity, and permeability, offering a versatile tool for material characterization with experimental validation.

Contribution

The paper presents a novel sensor design that operates in both capacitive and inductive modes, enabling simultaneous measurement of dielectric and conductive materials.

Findings

Effective dual modality measurement demonstrated experimentally

Sensor sensitive to permittivity, conductivity, and permeability

Design integrates planar spiral coils for combined sensing modes

Abstract

In this paper, an electromagnetic sensor which can operate simultaneously in capacitive and inductive modalities with sensitivities to permittivity, conductivity, and permeability is developed, and a novel measurement strategy is proposed accordingly. The sensor is composed of two planar spiral coils with a track width of 4 mm, which promotes its capacitive mode. The capacitive coupling is measured in common mode, while the inductive coupling is measured in differential mode. In capacitive mode, the sensor is sensitive to changes in permittivity, i.e., the dielectric material distribution; while in inductive mode, it is sensitive to magnetically permeable material and electrically conductive material. Furthermore, it is demonstrated that the sensor can simultaneously measure dielectric and conductive materials. This novel sensing element has been designed and implemented. Experimental results verified its effectiveness in dual modality measurement.