Topological resonance behaviors of surface acoustic wave under surface liquid-layer loadings and sensing applications

In this work, topological resonance behaviors of surface acoustic wave (SAW) under surface liquid-layer loadings are investigated. The results show that through the coupling of waveguide and resonant cavity, a resonant peak with high Q-factor can emerge, and the frequency of which is significantly sensitive to the liquid parameters. Based on that, a topological-resonance SAW liquid-phase sensor is proposed. The results show that the formation of the topological phase transition is closely related to the liquid-layer loading. Furthermore, by changing the thickness of the liquid-layer loading, the operating-frequency range of the device can be significantly expanded, which is vital for biomedical detecting applications. Based on which, the sensing performances of topological-resonance SAW liquid-phase sensor are simulated, which are used to sensing the concentration of albumin and hemoglobin concentration in blood, and high sensitivities and Q-factors can be obtained for this device. The results presented in this paper can provide an important basis for the realization of highly sensitive and stable SAW biomedical sensors in the future.