Modeling and simulation of a magnonic gas sensor to detected diseases in human breath

A theoretical study of the interaction between magnetostatic surface spin waves (MSWs) and magnetic nanoparticles (MNPs) is presented. The propagation of the MSW occurs on an yttrium iron garnet (YIG) thin film, and the MNPs are encapsulated in a tube. The operation of the sensor is based on the fact that a gas interacting with the nanostructures produces a change in their magnetization, and this, in turn, produces a measurable change in MSW propagation. The gas sensor structure is studied and characterized theoretically, through simulations. These simulations are also used in order to optimize the device through changes in the geometry, reaching sensitivities of 2 ppm in the magnetization of the sensitive material.