Sensing and simulation of self-inductance of a flat, circular coil in the presence of four water-based nanofluids

Abstract

Inductive sensors (ISs) are extremely sensitive sensing platforms that offer high resolution and currently serve as a relatively popular sensing platform for the detection of metals, nonmetals, and semiconductors. However, in spite of wonderful usability, there is a startling lack of IS implementation as a chemical sensor. Similarly, nanofluids (NFs) have gained more traction in the past decade since the physical properties of base fluids become heightened with the addition of nanoparticles (NPs). Regardless of these advantages, both areas lack studies regarding the behavior of NFs under a magnetic field (B-field). We show how a novel technique using a high-resolution, non-invasive inductance-to-digital converter (LDC) sensor is used to detect different NFs of varying physical properties. The LDC proves highly capable of not only serving as an extremely accurate and precise chemical sensor but also allowing us to determine how exposing several NFs to an inductor's B-field affects particle behavior in solution with extremely low signal and concentration detection limits. The four NF systems contain diamond, rutile, magnetite, and gold NPs where the sensor demonstrated superior sensitivity to gold-enhanced NFs. This exciting finding followed expected theoretical trends based on Faraday's laws of magnetism, and the experimental results were validated with finite element simulations within less than 1.0% error.