A microelectromechanical system-based terahertz spiral metamaterial for pneumatic pressure sensing applications.

Electromagnetic metamaterials have supported the realization of various highly effective sensors for chemical and biological detection. However, their application in pressure sensing has rarely been discussed. In this paper, we present a terahertz (THz) spiral metamaterial (TSM) integrated with microelectromechanical system (MEMS) technology for pneumatic pressure sensing applications. To improve the performance of the measuring range, the geometrical parameters of the TSM device are discussed, and the perfect absorption is achieved at 2.055 THz. Based on deformable construction, the TSM device can be designed for pneumatic pressure sensors, and the sensing performance is characterized by the relationship between resonant frequency and fluid pressure. The results show that the sensitivity of the TSM device to pressure force is 75 GHz kPa. Meanwhile, the behavior of the TSM device exposed to an ambient environment with different refraction indices indicates its potential for biochemical sensing, and the sensitivity is up to 1.290 THz per RIU. These results offer a practical and compact multifunctional sensor for biochemical and pressure detection and open an avenue for applications in the field of THz optoelectronics.