A Dual Sensitivity Amplification Strategy for Enhancing Low-Concentration Gas Detection Employing Mode Localization and Adsorption Expansion

This chapter delves into the advancement of resonant mass sensors for high-sensitivity gas detection, addressing the critical issue of enhancing sensitivity through structural and material adjustments. The study introduces a novel dual amplification strategy that combines mode localization and adsorption expansion, significantly improving gas sensitivity. Mode localization, initially predicted by Anderson P. and later investigated by Spletzer et al., is enhanced by introducing perturbations in both mass and stiffness through adsorption expansion. The chapter presents a detailed design of a resonant gas sensor featuring microscale clamped–clamped beams interconnected by a mechanical overhang. Upon gas adsorption, the sensor undergoes axial compressive strain, reducing bending stiffness and augmenting effective mass, thereby enhancing sensitivity. The governing equations for the model are derived using the Euler-Bernoulli beam theory and solved using a finite element approach based on the Galerkin method. Numerical simulations and equivalent experiments validate the effectiveness of the proposed method, demonstrating enhanced frequency shifts and amplitude variations with increasing expansion coefficients and gas concentrations. The chapter concludes by highlighting the potential applications of this dual amplification strategy in low-concentration gas leak analysis, exhaled gas composition analysis, and other industrial settings requiring precise gas sensing.