EM metamaterials sensor based on close coupling of spoof localized surface plasmons

Electromagnetic (EM) metamaterials, with their unparalleled ability to manipulate EM waves, hold significant potential in various fields, including telemetric sensing, which enables wireless measurement of strain and displacement. This paper explores a type of wireless sensor based on spoof localized surface plasmons (SLSPs) that generate a resonant evanescent EM wave. When closely coupled, their transmission spectrum is highly sensitive to the distance between the resonators, facilitating near-field measurement of strain and deformation. The theoretical foundation for telemetric measurement using this type of metamaterials is discussed, and a series of tests were conducted for validation. The results indicate a sensitivity of 36 MHz/millimeter at an operating frequency of 4.3 GHz. Both sensors can also be fabricated using printed circuit board (PCB) techniques.