Sustainable energy harvesting technologies with next-generation 3D magnetic nanostructures and nanocomposites

There are numerous energy sources that are abundant in our environment but are under-utilized. One example is magnetic noise (energy) generated by electrical power systems and from a variety of electronic devices. Other abundant energy sources include sunlight and wind energy, which can be harvested and converted into useful electricity using variously developed energy harvesting technologies and more recently, nanogenerators. Conventional approaches to energy harvesting have included systems that can harness geothermal energy and/or mechanical (human or natural) motions in addition to the aforementioned energy sources. In light of the recent developments in processes driven by nanotechnology, energy harvesting technologies for sustainable use include, among other elements, novel pathways for the preparation of multifunctional 2 and/or 3-dimensional (2/3D) nanomaterials/magnetic nanostructures of various compositions, shapes, and sizes. This aims to overcome some of the current technical limitations of inorganic bulk materials-based energy devices and systems by developing soft, flexible, adaptable and miniaturized energy harvesting devices. In this chapter, we discuss various perspectives on energy harvesting technologies, focusing on using nanostructured materials to redefine the field. We emphasize the significance of the new generation of 3D magnetic nanostructures and nanocomposites as relevant constituent materials for the fabrication of cutting-edge sustainable magnetic nanogenerators for harvesting freely available ambient magnetic (energy) “noise”. We also examine how, with the help of nanotechnology and nanoscience, this development could potentially reduce reliance on batteries, thereby benefiting the rapidly growing industrial automation and contemporary society at a sustainable scale.