Geometrically Curved Magnetic Field Sensors for Interactive Electronics

The concept of curvilinear magnetism can be applied to a wide range of materials and targets the applications where the interplay of geometry, shape, and magnetic texture arises. A clear advantage of these deformable magnetic materials is that they can be used for applications that demand flexibility or stretchability, something that conventionally rigid ferromagnets cannot provide. This advantage can be readily exploited in the field of flexible electronics, which aims to create electronic circuits and devices that can be folded or bent upon usage. The firm link between the fundamentals and applications of curved magnetic thin films is given by the fact that magnetic domain walls can be pinned at bends. This fundamental discovery has deep consequences for magnetic field sensors based on geometrically curved magnetic thin films. Indeed, curvature of the structure results in an additional pinning mechanism for domain walls, which can lead to the enhancement of the coercive field and hence lower the sensitivity of magnetic field sensors. These considerations came up very recently and its consequences are still to be explored and confirmed experimentally. Here, we will discuss primary the current advances in the application of flexible magnetic field sensors based on geometrically curved magnetic thin films and multilayers. Based on this technology, we present and foresee a wide range of applications in the fields of eMobility, health, and interactive electronics. The latter is the main focus of this chapter, in particular due to the added value of flexible magnetoelectronics to the fields of human-machine interfaces and virtual or augmented reality.