“…18 Toroidal metamaterials were also studied for their application in metamodulators, immunosensors, and refractive index sensors. 19 The performance of metamaterials mainly depends on their structural characteristics, 20 rather than their material properties. 21,22 Metamaterials are used in many applications, such as invisibility cloaks, 23 superlenses, 24 negative refraction, 25 and solar cells.…”