Novel Helmholtz resonators parallel to lateral closed resonators for sensing applications.

This study looks into the design of Helmholtz resonators along with lateral closed resonators for sensing applications, mainly for gas sample detection. A periodic parallel arrangement of both Helmholtz resonator and closed resonators was studied, while one resonator was defected to study the performance of the system. A relevant study was carried out in terms of numerical simulations with available data in the finite element method that give insight into the acoustic wave transmission and resonant frequencies of the system with or without defect. The study presented that due to the defect, highly localized modes deriving at lower spatial frequencies are induced within the system, making it highly sensitive to fine shifts of frequency. This sensitivity enables it to detect a wide variety of gas samples. Further, increasing the number of periods to 9 resulted in optimal performance, with significant improvements in sensitivity, quality factor, and detection limit. The study discusses the impact of geometric parameters and gas properties on system sensitivity, quality factor, and detection limit, indicating high potential for precision in sensing use for environmental monitoring and biosensing. The proposed sensor demonstrates exceptional selectivity in gas mixtures and maintains robust stability across a wide range of operating temperatures.