Magnetic field sensors are widely being used for various applications, ranging from navigation to industrial as well as biomedical applications. A large variety of magnetic sensors based on miniaturized and integrated Hall effect and magnetoresistive (MR) sensors to bulky superconducting quantum interference devices (SQUIDs) have been employed in automotive, information storage, and medical marketplaces. Biomedical magnetic sensors which can capture magnetic fields from biological tissues (e.g. brain, muscle, and cardiac) as well as point‐of‐care diagnostics were in the center of attention in the past couple of decades. In this regard, highly sensitive, low noise, low power, and integrated magnetic sensors are required to be portable, wearable, and implantable. This book presents the progress and state‐of‐the‐art toward this direction.

As one of the most well‐known magnetic sensors, Hall sensors are compact and versatile devices, exhibiting a high magnetic moment sensitivity over a wide field range in both low and room temperature conditions. Moreover, they generally offer a highly linear response, without being affected by magnetic saturation. These sensors have been studied and investigated both numerically and experimentally for different medical applications, such as Hall magnetometry on nanostructures and detection of magnetic beads as a label.

Among the magnetic sensors, it has always been to the benefit of MR sensors that thin‐film technology and large magnetoresistance were the interested objects of other often better financially supported activities. For fundamental physics, the investigations of phenomena in thin magnetic films were always valuable because it was easier to explain and understand the magnetism in this specific form of magnetic materials. The most significant support for researches of the magnetoresistance in thin film arises from the success of random access memory technology because it is obvious that the next generation of high‐density recording heads will be based on large MR effects.

In this book, the physics of magnetic sensors, their fabrication technologies, and applications are presented. For example, the technology of giant magnetoresistive (GMR) sensors is very sophisticated and refined and therefore it is described as an excellent example of the thin‐film technology. Thus, this book not only describes some classes of magnetic sensors but also discusses many more universal subjects, such as magnetism, thin‐film technology, fabrication techniques, magnetic measurements, and applications. Therefore, it should be useful for various kinds of readers, especially addressed to engineers. For high-quality specialists, it should be interesting as a comprehensive review of all available knowledge to date. For the sensors’ working mechanism, the mathematical descriptions are also presented; therefore, the level is also applicable to students and practising engineers. In this book, there is much computational information about magnetic sensor performance because the authors are engineers who have been active for numerous years in the field of designing and computational modeling of different magnetic sensors and also magnetic measurements.

As one of the most important applications for magnetic sensors, biomedical applications have been addressed and discussed comprehensively. For example, Hall sensors for the detection and even counting of individual magnetic nanobeads, which can be used as labels for medical imaging, drug delivery, and manipulation of biological species, have been discussed. MR sensors for detection of bioanalytes, monitoring of magnetic fluids, biomolecular recognition experiments, and neural activity recording as an ultrasensitive magnetic array have been addressed. We have also presented applications of nuclear magnetic resonance (NMR) sensors for magnetic resonance imaging, electron spin resonance (ESR) sensors for direct detection of paramagnetic species and ESR oximetry, as well as SQUIDs for biomagnetism, magnetoencephalography, and magnetocardiography. That is why this book is entitled “magnetic sensors for biomedical applications.”

All parts of the book, Hall effect, MR, NMR, and SQUID sensors and their applications, are written as separate chapters (with independent references and independent logical concept). So, it is not necessary to read the book “from the beginning.” If, for example, readers are interested in the one specific sensor, it is sufficient to read only the relevant chapter. In all parts, the structure is the same, consisting of overview, sensor structure and working mechanism theory, sensor different classes, and finally applications. Therefore, it is worth reading this book to gain a better understanding of the features of magnetic sensors and hopefully to use them more effectively. In addition, the authors also recommend reading this book as a story that is one of the most fascinating events of advanced technology. The sensors fabricated in nanometric atomic scale exhibit extraordinary and not fully understood phenomena. The expected future applications of magnetic sensors, especially in medical applications and data storage systems, open new perspectives for the whole of science.