Magnetic Micro and Nano Sensors for Continuous Health Monitoring

Abstract

Magnetic micro and nano sensors can be used in a broad variety of applications, e.g., for navigation, automotives, smartphones and also for health monitoring. Based on physical effects such as the well-known magnetic induction, the Hall effect, tunnel magnetoresistance and giant magnetoresistance, they can be used to measure positions, flow, pressure and other physical properties. In biomedicine and healthcare, these miniaturized sensors can be either integrated into garments and other wearables, be directed through the body by passive capsules or active micro-robots or be implanted, which usually necessitates bio-functionalization and avoiding cell-toxic materials. This review describes the physical effects that can be applied in these sensors and discusses the most recent micro and nano sensors developed for healthcare applications.

A Review of Characterization Techniques for Ferromagnetic Nanoparticles and the Magnetic Sensing Perspective

“…The magnetometer is a widely used device for many scopes, including biomedical purposes, geophysical studies, non-destructive testing, and catalytic materials characterization [58]. To serve the last scope, namely magnetic nanoparticle sensing, in the international literature exist several magnetometers, like the vibrating sample magnetometers (VSM), the optically pumped magnetometers (OPM), the magneto-optical Kerr effect magnetometers, the giant magnetoresistive sensors (GMR) [37,59], the alternating gradient magnetometers, the Faraday rotation magnetometers, the Hall effect magnetometers, the superconducting quantum interference devices (SQUIDs), the fluxgate magnetometers, etc., each with different sensitivity and cost [60,61]. In this paragraph, the most important types of magnetometers are presented and compared with their advantages and disadvantages.…”